Agilent Technologies Video Gaming Accessories 664xA User Manual
OPERATING GUIDE  
GPIB DC POWER SUPPLIES  
Agilent Technologies Models  
664xA, 665xA, 667xA, and 668xA  
AGILENT Model 6641A: 3217A-00111 and Above *  
AGILENT Model 6642A: 3204A-00111 and Above *  
AGILENT Model 6643A: 3205A-00111 and Above *  
AGILENT Model 6644A: 3213A-00111 and Above *  
AGILENT Model 6645A: 3215A-00111 and Above *  
AGILENT Model 6651A: 3130A-00171 and Above *  
AGILENT Model 6652A: 3201A-00381 and Above *  
AGILENT Model 6653A: 3145A-00551 and Above *  
AGILENT Model 6654A: 3148A-00391 and Above *  
AGILENT Model 6655A: 3152A-00176 and Above *  
AGILENT Model 6671A: 3129A-00218 and Above *  
AGILENT Model 6672A: 3138A-00101 and Above *  
AGILENT Model 6673A: 3138A-00101 and Above *  
AGILENT Model 6674A: 3133A-00161 and Above *  
AGILENT Model 6675A: 3138A-00101 and Above *  
AGILENT Model 6680A: 3302A-00101 and Above *  
AGILENT Model 6681A: 3250A-00101 and Above *  
AGILENT Model 6682A: 3339A-00101 and Above *  
AGILENT Model 6683A: 3339A-00161 and Above *  
AGILENT Model 6684A: 3339A-00101 and Above *  
* For instruments with higher Serial Numbers, a change page may be included.  
S1  
Agilent Part No. 5961-2579  
Microfiche Part No. 5961-2580  
Printed in USA: March 1995  
Reprinted: April 2000  
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SAFETY SUMMARY  
The following general safety precautions must be observed during all phases of operation, service, and repair of this  
instrument. Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety  
standards of design, manufacture, and intended use of the instrument. Agilent Technologies assumes no liability for the  
customer’s failure to comply with these requirements.  
BEFORE APPLYING POWER.  
Verify that the product is set to match the available line voltage and the correct fuse is installed.  
GROUND THE INSTRUMENT.  
This product is a Safety Class 1 instrument (provided with a protective earth terminal). To minimize shock hazard, the instrument chassis  
and cabinet must be connected to an electrical ground. The instrument must be connected to the ac power supply mains through a three-  
conductor power cable, with the third wire firmly connected to an electrical ground (safety ground) at the power outlet. For instruments  
designed to be hard-wired to the ac power lines (supply mains), connect the protective earth terminal to a protective conductor before any  
other connection is made. Any interruption of the protective (grounding) conductor or disconnection of the protective earth terminal will  
cause a potential shock hazard that could result in personal injury. If the instrument is to be energized via an external autotransformer for  
voltage reduction, be certain that the autotransformer common terminal is connected to the neutral (earthed pole) of the ac power lines  
(supply mains).  
FUSES.  
Only fuses with the required rated current, voltage, and specified type (normal blow, time delay, etc.) should be used. Do not use repaired  
fuses or short circuited fuseholders. To do so could cause a shock or fire hazard.  
DO NOT OPERATE IN AN EXPLOSIVE ATMOSPHERE.  
Do not operate the instrument in the presence of flammable gases or fumes.  
KEEP AWAY FROM LIVE CIRCUITS.  
Operating personnel must not remove instrument covers. Component replacement and internal adjustments must be made by qualified  
service personnel. Do not replace components with power cable connected. Under certain conditions, dangerous voltages may exist even  
with the power cable removed. To avoid injuries, always disconnect power, discharge circuits and remove external voltage sources before  
touching components.  
DO NOT SERVICE OR ADJUST ALONE.  
Do not attempt internal service or adjustment unless another person, capable of rendering first aid and resuscitation, is present.  
DO NOT EXCEED INPUT RATINGS.  
This instrument may be equipped with a line filter to reduce electromagnetic interference and must be connected to a properly grounded  
receptacle to minimize electric shock hazard. Operation at line voltages or frequencies in excess of those stated on the data plate may  
cause leakage currents in excess of 5.0 mA peak.  
SAFETY SYMBOLS.  
Instruction manual symbol: the product will be marked with this symbol when it is necessary for the user to refer to the  
instruction manual (refer to Table of Contents) .  
Indicates hazardous voltages.  
Indicate earth (ground) terminal.  
The WARNING sign denotes a hazard. It calls attention to a procedure, practice, or the like, which, if not correctly  
performed or adhered to, could result in personal injury. Do not proceed beyond a WARNING sign until the  
indicated conditions are fully understood and met.  
The CAUTION sign denotes a hazard. It calls attention to an operating procedure, or the like, which, if not correctly  
performed or adhered to, could result in damage to or destruction of part or all of the product. Do not proceed  
beyond a CAUTION sign until the indicated conditions are fully understood and met.  
DO NOT SUBSTITUTE PARTS OR MODIFY INSTRUMENT.  
Because of the danger of introducing additional hazards, do not install substitute parts or perform any unauthorized modification to the  
instrument. Return the instrument to an Agilent Technologies Sales and Service Offices for service and repair to ensure that safety  
features are maintained.  
Instruments which appear damaged or defective should be made inoperative and secured against unintended operation until they can be  
repaired by qualified service personnel.  
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SAFETY SUMMARY (continued)  
GENERAL  
Any LEDs used in this product are Class 1 LEDs as per IEC 825-l.  
ENVIRONMENTAL CONDITIONS  
With the exceptions noted, all instruments are intended for indoor use in an installation category II, pollution degree 2  
environment. They are designed to operate at a maximum relative humidity of 95% and at altitudes of up to 2000 meters.  
Refer to the specifications tables for the ac mains voltage requirements and ambient operating temperature range.  
Exceptions: Agilent Technologies Models 6680A, 6681A, 6682A, 6683A, 6684A, 6814A, and 6834A are intended for use  
in an installation category III environment.  
SAFETY SYMBOL DEFINITIONS  
Symbol  
Description  
Symbol  
Description  
Terminal for Line conductor on permanently  
installed equipment  
Direct current  
Alternating current  
Caution, risk of electric shock  
Both direct and alternating current  
Three-phase alternating current  
Earth (ground) terminal  
Caution, hot surface  
Caution (refer to accompanying documents)  
In position of a bi-stable push control  
Protective earth (ground) terminal  
Frame or chassis terminal  
Out position of a bi-stable push control  
On (supply)  
Terminal for Neutral conductor on permanently  
installed equipment  
Off (supply)  
Terminal is at earth potential(Used for  
measurement and control circuits designed to  
be operated with one terminal at earth  
potential.)  
Standby (supply)  
Units with this symbol are not completely  
disconnected from ac mains when this switch is  
off. To completely disconnect the unit from ac  
mains, either disconnect the power cord or  
have a qualified electrician install an external  
switch.  
Herstellerbescheinigung  
Diese Information steht im Zusammenhang mit den Anforderungen der Maschinenläminformationsverordnung vom 18  
Januar 1991.  
* Schalldruckpegel Lp <70 dB(A) * Am Arbeitsplatz * Normaler Betrieb * Nach EN 27779 (Typprufung).  
Manufacturer’s Declaration  
This statement is provided to comply with the requirements of the German Sound Emission Directive, from 18 January  
1991.  
* Sound Pressure Lp <70 dB(A) *At Operator Position * Normal Operation * According to EN 27779 (Type Test).  
4
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DECLARATION OF CONFORMITY  
according to ISO/IEC Guide 22 and EN 45014  
Manufacturer’s Name:  
Manufacturer’s Address:  
Agilent Technologies Inc.  
140 Green Pond Road  
Rockaway, New Jersey 07866  
U.S.A.  
declares that the Product  
Product Name:  
a) Single Output System Power Supply  
b) General Purpose Power Supply  
Model Number:  
a) Agilent 6641A, 6642A, 6643A, 6644A, 6645A  
b) Agilent 6541A, 6542A, 6543A, 6544A, 6545A  
conforms to the following Product Specifications:  
Safety:  
EMC:  
IEC 348:1978 / HD 401S1: 19811  
CISPR 11:1990 / EN 55011:1991 - Group 1 Class B  
IEC 801-2:1991 / EN 50082-1:1992 - 4 kV CD, 8 kV AD  
IEC 801-3:1984 / EN 50082-1:1992 - 3 V / m  
IEC 801-4:1988 / EN 50082-1:1992 - 0.5 kV Signal Lines  
1 kV Power Lines  
Supplementary Information:  
The product herewith complies with the requirements of the Low Voltage Directive  
73/23/EEC and the EMC Directive 89/336/EEC and carries the CE-marking accordingly.  
Note 1: The product family was introduced prior to 12/93.  
New Jersey  
Location  
January 1997  
Date  
Bruce Krueger / Quality Manager  
European Contact: Your local Agilent Technologies Sales and Service Office or Agilent Technologies GmbH,  
Department TRE, Herrenberger Strasse 130, D-71034 Boeblingen (FAX:+49-7031-14-3143)  
5
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DECLARATION OF CONFORMITY  
according to ISO/IEC Guide 22 and EN 45014  
Manufacturer’s Name:  
Manufacturer’s Address:  
Agilent Technologies Inc.  
140 Green Pond Road  
Rockaway, New Jersey 07866  
U.S.A.  
declares that the Product  
Product Name:  
a) Single Output System Power Supply  
b) General Purpose Power Supply  
Model Number:  
a) Agilent 6651A, 6652A, 6653A, 6654A, 6655A  
b) Agilent 6551A, 6552A, 6553A, 6554A, 6555A  
conforms to the following Product Specifications:  
Safety:  
EMC:  
IEC 348:1978 / HD 401S1: 19811  
CISPR 11:1990 / EN 55011:1991 - Group 1 Class B  
IEC 801-2:1991 / EN 50082-1:1992 - 4 kV CD, 8 kV AD  
IEC 801-3:1984 / EN 50082-1:1992 - 3 V / m  
IEC 801-4:1988 / EN 50082-1:1992 - 0.5 kV Signal Lines  
1 kV Power Lines  
Supplementary Information:  
The product herewith complies with the requirements of the Low Voltage Directive  
73/23/EEC and the EMC Directive 89/336/EEC and carries the CE-marking accordingly.  
Note 1: The product family was introduced prior to 12/93.  
New Jersey  
Location  
January 1997  
Date  
Bruce Krueger / Quality Manager  
European Contact: Your local Agilent Technologies Sales and Service Offices or Agilent Technologies GmbH,  
Department TRE, Herrenberger Strasse 130, D-71034 Boeblingen (FAX:+49-7031-14-3143)  
6
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DECLARATION OF CONFORMITY  
according to ISO/IEC Guide 22 and EN 45014  
Manufacturer’s Name:  
Manufacturer’s Address:  
Agilent Technologies Inc.  
140 Green Pond Road  
Rockaway, New Jersey 07866  
U.S.A.  
declares that the Product  
Product Name:  
a) Single Output System Power Supply  
b) General Purpose Power Supply  
Model Number:  
a) Agilent 6671A, 6672A, 6673A, 6674A, 6675A  
b) Agilent 6571A, 6572A, 6573A, 6754A, 6575A  
conforms to the following Product Specifications:  
Safety:  
EMC:  
IEC 348:1978 / HD 401S1: 19811  
CISPR 11:1990 / EN 55011:1991 - Group 1 Class B  
IEC 801-2:1991 / EN 50082-1:1992 - 4 kV CD, 8 kV AD  
IEC 801-3:1984 / EN 50082-1:1992 - 3 V / m  
IEC 801-4:1988 / EN 50082-1:1992 - 0.5 kV Signal Lines  
1 kV Power Lines  
Supplementary Information:  
The product herewith complies with the requirements of the Low Voltage Directive  
73/23/EEC and the EMC Directive 89/336/EEC and carries the CE-marking accordingly.  
Note 1: The product family was introduced prior to 12/93.  
New Jersey  
Location  
January 1997  
Date  
Bruce Krueger / Quality Manager  
European Contact: Your local Agilent Technologies Sales and Service Offices or Agilent Technologies GmbH,  
Department TRE, Herrenberger Strasse 130, D-71034 Boeblingen (FAX:+49-7031-14-3143)  
7
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DECLARATION OF CONFORMITY  
according to ISO/IEC Guide 22 and EN 45014  
Manufacturer’s Name:  
Manufacturer’s Address:  
Agilent Technologies Inc.  
140 Green Pond Road  
Rockaway, New Jersey 07866  
U.S.A.  
declares that the Product  
Product Name:  
Single Output System Power Supply  
Model Number:  
Agilent 6680A, 6681A, 6682A, 6683A, 6684A  
conforms to the following Product Specifications:  
Safety:  
EMC:  
IEC 348:1978 / HD 401S1: 19811  
CISPR 11:1990 / EN 55011:1991 - Group 1 Class A  
IEC 801-2:1991 / EN 50082-1:1992 - 4 kV CD, 8 kV AD  
IEC 801-3:1984 / EN 50082-1:1992 - 3 V / m  
IEC 801-4:1988 / EN 50082-1:1992 - 0.5 kV Signal Lines  
1 kV Power Lines  
Supplementary Information:  
The product herewith complies with the requirements of the Low Voltage Directive  
73/23/EEC and the EMC Directive 89/336/EEC and carries the CE-marking accordingly.  
Note 1: The product family was introduced prior to 12/93.  
New Jersey  
Location  
January 1997  
Date  
Bruce Krueger / Quality Manager  
European Contact: Your local Agilent Technologies Sales and Service Office or Agilent Technologies GmbH,  
Department TRE, Herrenberger Strasse 130, D-71034 Boeblingen (FAX:+49-7031-14-3143)  
PRINTING HISTORY  
The edition and current revision of this manual are indicated below. Reprints of this manual containing minor corrections  
and updates may have the same printing date. Revised editions are identified by a new printing date. A revised edition  
incorporates all new or corrected material since the previous printing date. Changes to the manual occurring between  
revisions are covered by change sheets shipped with the manual. In some cases, the manual change applies only to specific  
instruments. Instructions provided on the change sheet will indicate if a particular change applies only to certain  
instruments.  
Copyright 1993 Agilent Technologies Inc.  
Edition 1 - November, 1993  
Edition 2 - March, 1995  
Reprinted - April 2000  
This document contains proprietary information protected by copyright. All rights are reserved. No part of this document  
may be photocopied, reproduced, or translated into another language without the prior consent of Agilent Technologies.  
Information contained in this document is subject to change without notice.  
8
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Table Of Contents  
1
General Information  
Introduction...................................................................................................................................................15  
Safety Considerations................................................................................................................................16  
Instrument Identification ...........................................................................................................................16  
Options ......................................................................................................................................................16  
Accessories................................................................................................................................................17  
Description ................................................................................................................................................17  
Front Panel Programming........................................................................................................................18  
Remote Programming..............................................................................................................................18  
Analog Programming ..............................................................................................................................18  
Output Characteristic...............................................................................................................................19  
Specifications and Supplemental Characteristics ......................................................................................19  
Performance Specifications for Series 664xA .........................................................................................20  
Performance Specifications for Series 665xA .........................................................................................25  
Performance Specifications for Series 667xA .........................................................................................30  
Performance Specifications for Series 668xA .........................................................................................35  
Supplemental Characteristics for Series 664xA ......................................................................................21  
Supplemental Characteristics for Series 665xA ......................................................................................26  
Supplemental Characteristics for Series 667xA ......................................................................................31  
Supplemental Characteristics for Series 668xA ......................................................................................36  
Supplemental GPIB Characteristics for All Models................................................................................40  
Operator Replaceable Parts List ................................................................................................................41  
2
Installation  
Inspection ......................................................................................................................................................43  
Damage....................................................................................................................................................43  
Packaging Material..................................................................................................................................43  
Items Supplied.........................................................................................................................................43  
Location and Temperature.........................................................................................................................44  
Bench Operation......................................................................................................................................44  
Rack Mounting........................................................................................................................................44  
Temperature Performance .......................................................................................................................44  
Input Power Source ...................................................................................................................................45  
Series 664xA and 665xA Supplies ..........................................................................................................45  
Series 667xA Supplies.............................................................................................................................45  
Series 668xA Supplies.............................................................................................................................47  
3
Turn-on Checkout  
Introduction...................................................................................................................................................49  
Preliminary Checkout..................................................................................................................................49  
Power-on Checkout .....................................................................................................................................50  
Using the Keypad..........................................................................................................................................50  
Shifted Keys ..............................................................................................................................................50  
Backspace Key ..........................................................................................................................................50  
Output Checkout..........................................................................................................................................50  
Checking the Voltage Function .................................................................................................................51  
Checking the Current Function..................................................................................................................52  
Checking the Save and Recall Functions.....................................................................................................53  
Determining GPIB Address.........................................................................................................................53  
In Case of Trouble.......................................................................................................................................53  
Line Fuse...................................................................................................................................................53  
Condensation Fault (Series 668xA only)...................................................................................................55  
Error Messages..........................................................................................................................................55  
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4
User Connections  
Rear Panel Connections.................................................................................................................................57  
Load Wire Selection....................................................................................................................................57  
Analog Connector........................................................................................................................................58  
Digital Connector ........................................................................................................................................58  
Connecting Series 664xA and 665xA Power Supplies to the Load.............................................................59  
Output Isolation.........................................................................................................................................59  
Load Considerations..................................................................................................................................59  
Local Voltage Sensing ..............................................................................................................................60  
Remote Voltage Sensing ...........................................................................................................................61  
Operating Configurations ..........................................................................................................................63  
Connecting One Supply to the Load.........................................................................................................63  
Connecting Supplies in Auto-Parallel.......................................................................................................64  
Connecting Supplies in Series ..................................................................................................................65  
External Voltage Control...........................................................................................................................65  
Connecting Series 667xA Power Supplies to the Load ...............................................................................66  
Output Isolation.........................................................................................................................................66  
Load Considerations..................................................................................................................................67  
Local Voltage Sensing...............................................................................................................................68  
Remote Voltage Sensing ...........................................................................................................................68  
Operating Configurations ..........................................................................................................................70  
Connecting One Supply to a Single Load......................................................................................................70  
Connecting One Supply to Multiple Loads ..............................................................................................70  
Connecting Supplies in Auto-Parallel.......................................................................................................71  
Connecting Supplies in Series ..................................................................................................................72  
External Voltage Control...........................................................................................................................73  
Connecting Series 668xA Power Supplies to the Load ...............................................................................74  
Output Isolation.........................................................................................................................................74  
Load Considerations..................................................................................................................................74  
Local Voltage Sensing...............................................................................................................................75  
Remote Voltage Sensing ...........................................................................................................................75  
Operating Configurations ..........................................................................................................................76  
Connecting One Supply to a Single Load.................................................................................................77  
Connecting One Supply to Multiple Loads ..............................................................................................77  
Connecting Supplies in Auto-Parallel............................................................................................................78  
Connecting Supplies in Series .................................................................................................................78  
External Voltage Control...........................................................................................................................79  
Controller Connections..............................................................................................................................80  
Stand-Alone Connections........................................................................................................................80  
Linked Connections.................................................................................................................................80  
5
Front Panel Operation  
Introduction...................................................................................................................................................83  
Getting Acquainted.....................................................................................................................................83  
Programming the Output ............................................................................................................................86  
Introduction ...............................................................................................................................................86  
Establishing Initial Conditions. .................................................................................................................86  
Programming Voltage ...............................................................................................................................87  
Programming Overvoltage Protection .......................................................................................................87  
Programming Current................................................................................................................................88  
Programming Overcurrent Protection........................................................................................................89  
CV Mode vs. CC Mode..............................................................................................................................89  
Unregulated Operation ...............................................................................................................................90  
Saving and Recalling States ......................................................................................................................90  
Turn-on Conditions ...................................................................................................................................90  
Setting the GPIB Address..............................................................................................................................91  
10  
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A
Calibration  
Introduction...................................................................................................................................................93  
Equipment Required...................................................................................................................................93  
General Procedure ......................................................................................................................................93  
Parameters Calibrated................................................................................................................................93  
Test Setup..................................................................................................................................................94  
Front Panel Calibration .................................................................................................................................94  
Entering the Calibration Values ............................................................................................................... 94  
Saving the Calibration Constants...............................................................................................................94  
Disabling the Calibration Mode ................................................................................................................94  
Changing the Calibration Password............................................................................................................94  
Recovering From Calibration Problems .....................................................................................................97  
Calibration over the GPIB.............................................................................................................................98  
Calibration Example..................................................................................................................................98  
Calibration Language Dictionary ..............................................................................................................98  
CAL:CURR.............................................................................................................................................98  
CAL:CURR:LEV ....................................................................................................................................98  
CAL:CURR:MON (Series 668xA only)..................................................................................................99  
CAL:PASS ..............................................................................................................................................99  
CAL:SAVE .............................................................................................................................................99  
CAL:STAT..............................................................................................................................................99  
CAL:VOLT ...........................................................................................................................................100  
CAL:VOLT:LEV ..................................................................................................................................100  
CAL:VOLT:PROT................................................................................................................................100  
Agilent-Basic Calibration Program .........................................................................................................100  
B
Operation Verification  
Introduction.................................................................................................................................................103  
Test Equipment Required.........................................................................................................................103  
List of Equipment....................................................................................................................................103  
Current Monitoring Resistor....................................................................................................................103  
Performing the Tests ................................................................................................................................105  
General Measurement Techniques ..........................................................................................................105  
Programming the Power Supply..................................................................................................................105  
Order of Tests..........................................................................................................................................105  
Turn-on Checkout....................................................................................................................................105  
Voltage Programming and Readback Accuracy..........................................................................................105  
Current Programming and Readback Accuracy.......................................................................................106  
Verification Test Parameters ....................................................................................................................107  
C
D
Line Voltage Conversion  
Series 664xA and 665xA Supplies ..............................................................................................................115  
Series 667xA Supplies..............................................................................................................................116  
Series 668xA Supplies..............................................................................................................................117  
Digital Port Functions  
Digital Connector ........................................................................................................................................119  
Fault/Inhibit Operation.............................................................................................................................119  
Changing the Port Configuration.................................................................................................................122  
Digital I/O Operation...................................................................................................................................122  
Relay Link Operation ..................................................................................................................................123  
E
Current Loop Compensation  
Function of Loop Compensation .................................................................................................................125  
Setting the Loop Compensation Switch.......................................................................................................128  
11  
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F
Using Agilent 668xA Series Power Supplies in Autoparallel  
Auto parallel Procedure...............................................................................................................................129  
Index  
References...................................................................................................................................................131  
Agilent Sales and Support Offices  
Contacts.......................................................................................................................................................135  
12  
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List of Figures  
2-1.  
2-2.  
2-3.  
2-4.  
2-5.  
3-1.  
4-1.  
4-2.  
Series 664xA/665xA Power Connection..................................................................................45  
Connecting the Series 667xA Power Cord...............................................................................46  
667xA Connection to a 3-Phase Line.......................................................................................47  
Series 668xA Overall Wiring Diagram....................................................................................47  
Connecting the Series 668xA Power Cord...............................................................................48  
Series 667xA Line Fuse...........................................................................................................54  
Rear Panel Analog Connector..................................................................................................58  
Rear Panel Digital Connector ..................................................................................................58  
Series 664xA/665xA Rear Panel Output Connections.............................................................59  
Series 664xA/665xA Single Load Connection.........................................................................62  
Series 664xA/665xA Multiple Load Connection.....................................................................63  
Series 664xA/665xA Auto-Parallel Connection ......................................................................63  
Using Series Diodes with Series 664xA/665xA Auto-Parallel Operation................................64  
Series 664xA/665xA Series Connection..................................................................................65  
Series 664xA/665xA Analog Programming Connections ......................................................66  
Series 667xA Rear Panel Output Connections.........................................................................67  
Series 667xA Sense Lead Bypass Network..............................................................................70  
Series 667xA Single Load Connection ....................................................................................70  
Series 667xA Multiple Load Connection.................................................................................71  
Series 667xA Auto-Parallel Connection ..................................................................................71  
Series 667xA Series Connection..............................................................................................72  
Series 667xA Analog Programming Connections....................................................................73  
Series 668xA Rear Panel Output Connections.........................................................................74  
Series 668xA Sense Lead Bypass Network.............................................................................76  
Series 668xA Single Load Connection . ..................................................................................77  
Series 668xA Multiple Load Connection.................................................................................77  
Series 668xA Auto-Parallel Connection. .................................................................................78  
Series 668xA Series Connection..............................................................................................79  
Series 668xA Analog Programming Connections....................................................................80  
Controller Connections ............................................................................................................81  
Front Panel Controls and Indicators.........................................................................................84  
Typical Power Supply Operating Curve ..................................................................................87  
Calibration Test Setup..............................................................................................................95  
Agilent BASIC Calibration Program .....................................................................................101  
Verification Test Setup ..........................................................................................................104  
Series 664xA Line Select Switches........................................................................................115  
Series 665xA Line Select Jumpers.........................................................................................116  
Series 667xA Line Select Switch ..........................................................................................116  
Removing the Series 668xA Inner Cover...............................................................................118  
Series 668xA Line Conversion Jumpers ................................................................................118  
Digital Port Connector ...........................................................................................................119  
Example of Inhibit Input........................................................................................................120  
Examples of Fault Outputs.....................................................................................................121  
Digital Port Configuration Jumper.........................................................................................121  
Digital I/O Port Applications ................................................................................................122  
Relay Link Connections.........................................................................................................123  
CC Loop Compensation Curves for Series 668xA.................................................................126  
CC Loop Compensation Switch for Series 668xA.................................................................128  
Master/Slave Current Division...............................................................................................130  
4-3a.  
4-3b.  
4-3c.  
4-3d.  
4-3e.  
4-3f.  
4-3g.  
4-4a.  
4-4b.  
4-4c.  
4-4d.  
4-4e.  
4-4f.  
4-4g.  
4-5a.  
4-5b.  
4-5c.  
4-5d.  
4-5e.  
4-5f.  
4-5g.  
4-6.  
5-1.  
5-2.  
A-l.  
A-2.  
B-l.  
C-l.  
C-2.  
C-3.  
C-4.  
C-5.  
D-1.  
D-2.  
D-3.  
D-4.  
D-5.  
D-6.  
E-l.  
E-2.  
F-1.  
13  
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List of Tables  
l-la.  
l-lb.  
1-2a.  
1-2b.  
1-3a.  
1-3b.  
1-4a.  
1-4b.  
1-5.  
1-6.  
2-1.  
3-1.  
3-2.  
Performance Specifications - Series 664xA.............................................................................20  
Supplemental Characteristics - Series 664xA ..........................................................................21  
Performance Specifications - Series 665xA............................................................................25  
Supplemental Characteristics - Series 665xA ..........................................................................26  
Performance Specifications - Series 667xA............................................................................30  
Supplemental Characteristics - Series 667xA .........................................................................31  
Performance Specifications - Series 668xA.............................................................................35  
Supplemental Characteristics- Series 668xA ...........................................................................36  
Supplemental GPIB Characteristics for All Models ................................................................40  
Operator Replaceable Parts List...............................................................................................41  
Items Supplied .........................................................................................................................43  
Checking the Voltage Functions ..............................................................................................50  
Checking the Current Functions...............................................................................................52  
Power-on Selftest Errors ..........................................................................................................55  
Runtime Error Messages..........................................................................................................56  
Copper Wire Ampere Capacity and Resistance .......................................................................57  
Front Panel Controls and Indicators.........................................................................................84  
Equipment Required for Calibration........................................................................................93  
Typical Front Panel Calibration Procedure..............................................................................96  
GPIB Calibration Error Messages...........................................................................................97  
Equipment Required for Verification Tests ...........................................................................103  
Voltage Programming and Readback Accuracy Tests ...........................................................105  
Current Programming and Readback Accuracy Test .............................................................106  
Test Parameters for Series 664xA..........................................................................................107  
Test Parameters for Series 665xA..........................................................................................109  
Test Parameters for Series 667xA..........................................................................................111  
Test Parameters for Series 668xA..........................................................................................113  
Settings for CC Loop Compensation Switch..........................................................................125  
3-3.  
3-4.  
4-1.  
5-1.  
A-l.  
A-2.  
A-3.  
B-l.  
B-2.  
B-3.  
B-4.  
B-5.  
B-6.  
B-7.  
E-l.  
14  
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1
General Information  
Introduction  
Two guides are shipped with your power supply - an Operating Guide (this document) and a Programming Guide. You will  
find information on the following tasks in these guides:  
Quick Document Orientation1  
Topic  
Calibrating the power supply  
Location  
Appendix A - this guide  
Compatibility programming language  
Configuring the digital port  
Line voltage:  
Appendix B - Programming Guide  
Appendix D - this guide  
Connecting ac power source  
Converting the ac source voltage  
Source current, frequency, and power ratings  
Operator replaceable parts  
Operator troubleshooting  
Output impedance characteristics  
Power supply accessories  
Power supply operating characteristics  
Power supply options  
Chapter 2 - this guide  
Appendix B - this guide  
Chapter 1- this guide  
Chapter 1- this guide  
Chapter 3 - this guide  
Chapter 1- this guide  
Chapter 1- this guide  
Chapter 1- this guide  
Chapter 1- this guide  
Chapter 1- this guide  
Power supply performance specifications  
Programming  
discrete fault inhibit (DFI) operation  
from the analog port  
Chapter 4 - Programming Guide  
Chapter 4 - this guide  
from the front panel  
Chapter 5 - this guide  
over the GPIB  
remote inhibit (RI) operation  
status registers  
Quick operating checkout (without load)  
Rack mounting  
Chapter 2 - Programming Guide  
Chapter 4 - Programming Guide  
Chapter 4 - Programming Guide  
Chapter 3 - this guide  
Chapter 2 - this guide  
SCPI programming language  
Wiring  
Chapter 3 - Programming Guide  
analog programming port  
discrete fault indicator (DFI) operation  
digital port  
GPIB controller  
load or loads  
local sensing  
remote inhibit (RI) operation  
remote sensing  
Chapter 4 - this guide  
Appendix D - this guide  
Appendix D - this guide  
Chapter 4 - this guide  
Chapter 4 - this guide  
Chapter 4 - this guide  
Chapter 4 - this guide  
Chapter 4 - this guide  
1 See the Table of Contents for complete list of topics.  
General Information 15  
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Safety Considerations  
This power supply is a Safety Class 1 instrument, which means it has a protective earth terminal. That terminal must be  
connected to earth ground through a power source equipped with a 3-wire ground receptacle. Refer to the Safety Summary  
page at the beginning of this guide for general safety information. Before installation or operation, check the power supply  
and review this guide for safety warnings and instructions. Safety warnings for specific procedures are located at  
appropriate places in the guide.  
Instrument Identification  
The power supply is identified by a unique two-part serial number, such as, 3343A-00177. The first part, or prefix, is a  
number-letter combination that provides the following information:  
3343 = The year and week of manufacture or last significant design change. Add 1960 to the first two digits to determine  
the year. For example, 32=1992, 33=1993, etc. The last two digits specify the week of the year (43 = the 43rd  
week).  
A =  
The letter indicates the country of manufacture, where A = USA.  
Options  
List of Options  
Option  
Description  
Input power 100 Vac, nominal  
Input power 200 Vac, nominal  
Input power 220 Vac, nominal  
Input power 240 Vac, nominal  
Input power 360-440 Vac, 3 -phase  
Output connector kit required for bench applications  
Bus bar spacers for paralleling power supplies  
Power cord, 12 AWG, UL listed, CSA certified, without plug  
Power cord, 4 mm2, harmonized, without plug  
Power cord, 10 AWG, UL listed, CSA certified, without plug  
Power cord, 12 AWG, UL listed, CSA certified, with NEMA  
6-20P 20A/250V plug  
Used with Agilent Series  
664xA 665xA 667xA 668xA  
100  
200  
220  
240  
400  
601  
602  
831  
832  
834  
841  
x
x
x
x
x
x
x
x
x
x
x
x
x
x
842  
843  
844  
861  
Power cord, 4 mm2, harmonized, with IEC 309 32A/220V  
plug  
Power cord, 12 AWG, UL listed, CSA certified, with JIS  
C8303 25A/250V plug  
Power cord, 10 AWG, UL listed, CSA certified, with NEMA  
L6-30P-30A/250V locking plug  
x
x
x
Power cord, 10 AWG, UL listed, 300 V, CSA certified,  
without plug  
x
x
Power cord, 2.5 mm2, 4-wire, harmonized, without plug  
Rack mount kit (Agilent 5062-3974)  
862  
908  
x
Rack mount kit (Agilent 5062-3977) Support rails (E3663A)  
are required.  
x
x
Rack mount kit (Agilent 5062-3977 & 5062-3974) Support  
rails (E3663A) are required.  
x
16 General Information  
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List of Options (continued)  
Description  
Option  
Used with Agilent Series  
664xA 665xA 667xA 668xA  
909  
909  
Rack mount kit with handles (Agilent 5062-3975)  
Rack mount kit with handles (Agilent 5062-3983) Support  
rails (E3663A) are required.  
x
x
x
Rack mount kit with handles (Agilent 5062-3983 &  
5062-3974) Support rails (E3663A) are required.  
Service manual with extra Operating and Programming  
Guides  
x
x
910  
x
x
x
ABD  
ABE  
ABF  
ABJ  
ABZ  
AB0  
Quick-Start Guide German  
Quick-Start Guide, Spanish  
Quick-Start Guide, French  
Operating Manual, Japanese  
Quick-Start Guide, Italian  
Quick-Start Guide, Taiwanese  
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Accessories  
List of Accessories  
Description Agilent No.  
Agilent No.  
Fuse replacement kit for Series 668xA  
16 AM for 360-440 Vac, 3-phase line  
30 AM for 180-235 Vac, 3-phase line  
GPIB cable (all models)  
0.5 meters (1.6 ft)  
1.0 meter (3.3 ft)  
2.0 meters (6.6 ft)  
4.0 meters ( 13 .2 ft)  
5060-3512  
5060-3513  
10833D  
10833A  
10833B  
10833C  
Serial link cable (all models)  
2.0 meters (6.6 ft)  
5080-2148  
Slide mount kit  
heavy duty, for Series 667xA/668xA  
standard, for Series 664xA/665xA  
1494-0058  
1494-0059  
Description  
These units form a family of unipolar, GPIB programmable power supplies organized as follows:  
Family  
Power  
200 W  
500 W  
2000 W  
5000 W  
Models  
Series 664xA  
Series 665xA  
Series 667xA  
Series 668xA  
AGILENT 6641A, 6642A, 6643A, 6644A, 6645A  
AGILENT 6651A, 6652A, 6653A, 6654A, 6655A  
AGILENT 6671A, 6672A, 6673A, 6674A, 6675A  
AGILENT 6680A, 6681A, 6682A, 6683A, 6684A  
Each power supply is programmable locally from the front panel or remotely via a rear-panel analog control port.  
General Information 17  
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Operational features include:  
■
■
■
■
■
■
■
■
■
■
Constant voltage (CV) or constant current (CC) output over the rated output range.  
Built-in overvoltage (OV), overcurrent (OC), and overtemperature (OT) protection.  
Automatic turn-on selftest.  
Pushbutton nonvolatile storage and recall of up to 5 operating states (4 in Series 668xA supplies).  
Local or remote sensing of output voltage.  
Auto-parallel operation for increased total current.  
Series operation for increased total voltage.  
Analog input for remote programming of voltage and current.  
Voltage output for external monitoring of output current.  
User calibration from the front panel.  
Front Panel Programming  
The front panel has both rotary (RPG) and keypad controls for setting the output voltage and current. The panel display  
provides digital readouts of the output voltage and current. Other front panel controls permit:  
■
■
■
■
■
■
■
Enabling or disabling the output.  
Setting the overvoltage protection (OVP) trip voltage.  
Enabling or disabling the overcurrent protection (OCP) feature.  
Saving and recalling operating states.  
Setting the GPIB address.  
Reading GPIB error message codes.  
Calibrating the power supply, including changing the calibration protection password.  
Remote Programming  
The power supply may be remotely programmed via the GPIB bus and/or from an analog input port. GPIB programming is  
with SCPI (Standard Commands for Programmable Instruments) commands that make the power supply programs  
compatible with those of other GPIB instruments. (A software-controlled Compatibility Mode also permits programming in  
the command set of the Agilent 6030xA Autoranging Series.) In addition to control functions, SCPI programming permits  
writing to the front panel LCD and complete calibration functions. Power supply status registers permit remote monitoring  
of the following conditions:  
■
■
■
■
■
■
■
■
Overvoltage, overcurrent, overtemperature, and unregulated states.  
Operating mode (constant voltage or constant current).  
State of the RI (remote inhibit) input signal.  
Power-on status (PON).  
Status of the output queue (QYE).  
Pending triggers (WTG).  
GPIB interface programming errors (CME, DDE, and EXE).  
Calibration state (enabled or disabled).  
The status registers can be programmed to generate an output fault signal (FLT) upon the occurrence of one or more  
selected status events.  
Analog Programming  
The power supply has an analog port for remote programming. The output voltage and/or current of the power supply may  
be controlled by individual d-c programming voltages applied to this port. The port also provides a monitor output that  
supplies a d-c voltage proportional to the output current.  
18 General Information  
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Output Characteristic  
General  
The power supply can operate in either CV (constant voltage) or CC (constant current) over its voltage and current ratings  
(see Table 1-l). The operating locus is shown by the Output Characteristic Curve in Table 1-2. The operating point is  
determined by the voltage setting (Vs), the current setting (Is), and the load impedance. Two operating points are shown.  
Point 1 is defined by the load line cutting the operating locus in the constant-voltage region. This region defines the CV  
mode. Point 2 is defined by the load line cutting the operating locus in the constant-current region. This region defines the  
CC mode.  
Downprogramming  
The power supply can sink current for more rapid down programming in the CV mode. For Series 664xA and 665xA  
supplies, this capability is defined by the second quadrant area (-Is) of the Output Characteristic Curve. These supplies can  
sink about 20% of their maximum rated positive output current. For Series 667xA and 668xA power supplies, this is an  
uncharacterized current-sinking area that provides a limited downprogramming capability.  
Specifications and Supplemental Characteristics  
Tables 1-1 through 1-4 list the specifications and supplemental characteristics for the Series 664xA, 665xA, 667xA, and  
668xA power supplies. The organization is as follows:  
Series  
Specifications  
Table l-la  
Table 1-2a  
Table 1-3a  
Table 1-4a  
Characteristics  
Table l-lb  
6641A-6645A  
6651A-6655A  
6671A-6675A  
6680A-6684A  
Table 1-2b  
Table 1-3b  
Table 1-4b  
Specifications are performance parameters warranted over the specified temperature range.  
Supplemental Characteristics are not warranted but are descriptions of performance determined either by design or type  
testing.  
General Information 19  
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Table 1-1a. Performance Specifications for Series 664xA1  
Agilent Model Number  
Parameter  
Output Ratings  
6641A  
6642A  
6643A  
6644A  
6645A  
Voltage:  
0 - 8 V  
0 - 20 A  
0 - 18 A  
0 - 17 A  
0 - 20 V  
0 - 10 A  
0 - 9 A  
0 - 35 V  
0 - 6 A  
0 - 5.4 A  
0 - 5.1 A  
0 - 60 V  
0 - 3.5 A  
0 - 3.2 A  
0 - 3.0 A  
0 - 120 V  
0 - 1.5 A  
0 - 1.4 A  
0 -1.4 A  
Current:@ 40°C  
Current:@ 50°C  
Current:@ 55°C  
0 - 8.5 A  
Programming Accuracy (@ 25 ± 5 °C)  
Voltage:  
0.06% +  
5 mV  
10 mV  
13 mA  
15 mV  
6.7 mA  
26 mV  
4.1 mA  
51 mV  
1.7 mA  
Current:  
0 . l5 % +  
26 mA  
Ripple & Noise (from 20 Hz to 20 MHz with outputs ungrounded, or with either output terminal grounded)  
Constant Voltage:  
Constant Voltage:  
Constant Current:  
rms  
p-p  
rms  
300 µV  
3 mV  
10 mA  
300 µV  
3 mV  
5 mA  
400 µV  
4 mV  
3 mA  
500 µV  
5 mV  
1.5 mA  
700 µV  
7 mV  
1 mA  
Readback Accuracy (from front panel or over GPIB with respect to actual output @ 25 ±:5 °C)  
Voltage:  
+Current  
-Current  
0.07% +  
0.15% +  
0.35% +  
6 mV  
18 mA  
40 mA  
15 mV  
9.1 mA  
20 mA  
25 mV  
5 mA  
40 mV  
3 mA  
6.8 mA  
80 mV  
1.3 mA  
2.9 mA  
12 mA  
Load Regulation (change in output voltage or current for any load change within ratings)  
Voltage  
Current:  
1 mV  
1 mA  
2 mV  
0.5 mA  
3 mV  
0.25 mA  
4 mV  
0.25 mA  
5 mV  
0.25 mA  
Line Regulation (change in output voltage or current for any line change within ratings  
Voltage:  
Current:  
0.5 mV  
1 mA  
0.5 mV  
0.5 mA  
1 mV  
0.25 mA  
1 mV  
0.25 mA  
2 mV  
0.25 mA  
Transient Response Time (for the output voltage to recover to its previous level (within 0.1% of the rated voltage or  
20 mV, whichever is greater) following any step change in load current up to 50% of the rated current.  
< 100 µs  
AC Input Ratings (selectable via internal switching - see Appendix B)  
Nominal line voltage  
100,120,220,240 Vac:  
230 Vac:  
F requency range:  
-13%, +6 %  
-10%, +10%  
47-63 Hz  
Output Terminal Isolation  
±240 Vdc (maximum, from chassis ground)  
Notes: 1For Supplemental Characteristics, see Table 1-1b.  
20 General Information  
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Table 1-1b. Supplemental Characteristics for Series 664xA1  
Agilent Model Number  
Parameter  
6641A  
6642A  
6643A  
6644A  
6645A  
Output Programming Range (maximum programmable values)  
Voltage:  
Current:  
Overvoltage Protection (OVP):  
8.190 V  
20.475 A  
8.8 V  
20.475 V  
10.237 A  
22.0 V  
35.831 V  
6.142 A  
38.5 V  
61.425 V  
3.583 A  
66.0 V  
122.85 V  
1.535 A  
132.0 V  
Average Resolution  
Voltage:  
Current:  
2 mV  
6 mA  
13 mV  
5 mV  
3 mA  
30 mV  
10 mV  
2 mA  
54 mV  
15 mV  
1.2 mA  
93 mV  
30 mV  
0.5 mA  
190 mV  
Overvoltage Protection (OVP):  
Accuracy  
Overvoltage Protection (OVP):  
Analog Programming (VP):*  
0.36% +  
Analog Programming (IP):*  
7.6% +  
160 mV  
6 mV  
400 mV  
15 mV  
9.2 mA  
700 mV  
27 mV  
1.2 V  
2.4 V  
45 mV  
90 mV  
18 mA  
1.5% +  
5.5 mA  
8.1 mA  
3.2 mA  
7.1 mA  
1.4 mA  
1.8 mA  
Current Monitor (+IM):*  
7.7% +  
1.6 % +  
65 mA  
32 mA  
*Referenced to supply output  
Drift Temperature Stability (following a 30-minute warmup, change in output over 8 hours under constant line, load,  
and ambient temperature)  
Voltage:  
Current:  
0.02% +  
0.02% +  
0.4 mV  
16 mA  
1 mV  
6 mA  
2 mV  
3 mA  
3 mV  
2 mA  
6 mV  
1 mA  
Temperature Coefficients (change per °C)  
Voltage:  
+Current:  
Voltage Readback:  
+Current Readback:  
--Current Readback:  
60 ppm +  
95 ppm +  
60 ppm +  
95 ppm +  
110 ppm +  
0.1 mV  
0.82 mA  
0.2 mV  
1.2 mA  
1.2 mA  
0.2 mV  
0.41 mA  
0.5 mV  
0.62 mA  
0.62 mA  
0.3 mV  
0.18 mA  
0.75 mV  
0.33 mA  
0.33 mA  
0.5 mV  
0.12 mA  
1.3 mV  
0.20 mA  
0.20 mA  
1.1 mV  
0.04 mA  
2.6 mV  
0.08 mA  
0.08 mA  
Overvoltage Protection (OVP):  
200 ppm +  
1.6 mV  
0.1 mV  
3.3 mV  
0.25 mV  
0.28 mA  
0.3 mA  
5 mV  
13 mV  
0.7 mV  
0.1 mA  
0.06 mA  
24 mV  
1.25 mV  
0.04 mA  
0.02 mA  
Analog Programming (VP):  
Analog Programming (IP):  
Current Monitor (+IM):  
Maximum Input Power:  
60 ppm +  
90 ppm +  
75 ppm +  
0.4 mV  
0.17 mA  
0.06 mA  
0.56 mA  
0.61 mA  
480 VA; 400 W, 60 W with no load  
Notes:  
1For Performance Specifications, see Table 1-la.  
:
General Information 21  
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Table 1-lb. Supplemental Characteristics for Series 664xA (continued)1  
Parameter  
Agilent Model Number  
6641A  
6642A  
6643A  
6644A  
6645A  
Maximum AC Line Current Ratings  
100 Vac nominal:  
120 Vac nominal:  
220 Vac nominal:  
230 Vac nominal:  
4.4 A rms  
3.8 A rms  
2.2 A rms  
2.1 A rms  
2.0 A rms  
240 Vac nominal:  
Maximum Reverse Bias Current:  
With AC input power applied and the dc output reverse  
biased by an external dc source, the supply will continuously  
withstand without damage a current equal to its output  
current rating (see Table 1- 1a).  
Remote Sensing Capability  
Voltage Drop Per Lead:  
Up to 1/2 of rated output voltage.  
Load Regulation:  
Load Voltage:  
Add 3 mV to spec (see Table l-la) for each l-volt change in  
the + output lead due to load current changes.  
Subtract voltage drop in load leads from specified output  
voltage rating.  
Command Processing Time (Average time for output voltage to change after receipt of digital data when the supply  
is connected directly to the GPIB Bus):  
20 ms  
Downprogrammer Current Capability (± 15%):  
5.8 A  
2.5 A  
1.5 A  
0.9 A  
0.75 A  
Output Voltage Programming Response Time  
Rise/Fall Time (time for output to change from 90 % to 10% or from 10% to 90% of its total excursion):  
<15 ms  
Settling Time (time for output change to settle within 1 LSB (0.025% x rated voltage) of its final value):  
<60 ms  
Monotonicity:  
Output is monotonic over entire rated voltage, current, and  
temperature range.  
Auto-Parallel Configuration:  
Up to 3 identical models  
Analog Programming (IP & VP)  
Input Signal:*  
0 to -5 V  
Input Impedance:  
*Signal source must be isolated.  
10 kΩ, nominal  
Current Monitor Output (+IM):  
0 to -5 V represents zero to full-scale current output  
Savable States  
Nonvolatile Memory Locations:  
Nonvolatile Memory Write Cycles:  
Prestored State (factory default):  
5 ( 0 through 4)  
40,000, typical  
Location 0  
Notes: lFor Performance Specifications, see Table l-la.  
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Table 1-1b. Supplemental Characteristics for Series 664xA (continued)1  
Parameter  
Digital Port Characteristics  
All Models  
(see Table 1-5)  
GPIB Interface Capabilities  
Serial Link Capabilities  
(see Table 1-5)  
(see Table 1-5)  
1 year  
Recommended Calibration Interval:  
Safety Compliance  
Complies with:  
Designed to comply with:  
CSA 22.2 No.231,IEC 348  
UL 1244  
RFI Suppression (complies with):  
CISPR-ll, Group 1, Class B  
Dimensions  
Width:  
425.5 mm (16.75 in)  
88.1 mm (3.5 in)  
439 mm (17.3 in)  
Height (including removable feet):  
Depth (including safety cover):  
Note 1: For Performance Specifications, see Table l-la.:  
Weight  
Net:  
Shipping:  
14.2 kg (31.4 lb)  
16.3 kg (36 lb)  
Output Characteristic Curve:  
Notes: lFor Performance Specifications, see Table l-la.  
General Information 23  
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Table 1-1b. Supplemental Characteristics for Series 664xA (continued)1  
Parameter  
All Models  
Output Impedance Curves (Typical):  
Notes: lFor Performance Specifications, see Table l-la.  
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Table 1-2a. Performance Specifications for Series 665xA1  
Agilent Model Number  
Parameter  
Output Ratings  
6651A  
6652A  
6653A  
6654A  
6655A  
Voltage:  
0 - 8 V  
0 - 50 A  
0 - 45 A  
0 - 42.5 A  
0 - 20 V  
0 - 25 A  
0 - 22.5 A  
0 - 21.3 A  
0- 35 V  
0 - 15 A  
0 - 13.5 A  
0 - 12.8 A  
0 - 60 V  
0 - 9 A  
0 - 8.1 A  
0 - 7.7 A  
0 - 120 V  
0 - 4 A  
0 - 3.6 A  
0 -3.4 A  
Current:@ 40°C  
Current:@ 50°C  
Current:@ 55°C  
Programming Accuracy (@ 25 ± 5 °C)  
Voltage:  
0.06% +  
5 mV  
10 mV  
25 mA  
15 mV  
13 mA  
26 mV  
8 mA  
51 mV  
4 mA  
Current:  
0 . l5 % +  
60 mA  
Ripple & Noise (from 20 Hz to 20 MHz with outputs ungrounded, or with either output terminal grounded)  
Constant Voltage:  
Constant Voltage:  
Constant Current:  
rms  
p-p  
rms  
300 µV  
3 mV  
25 mA  
300 µV  
3 mV  
10 mA  
400 µV  
4 mV  
5 mA  
500 µV  
5 mV  
3 mA  
700 µV  
7 mV  
2 mA  
Readback Accuracy (from front panel or over GPIB with respect to actual output @ 25 ± 5 °C)  
Voltage:  
+Current  
-Current  
0.07% +  
0.15% +  
0.35% +  
6 mV  
67 mA  
100 mA  
15 mV  
26 mA  
44 mA  
25 mV  
15 mA  
24 mA  
40 mV  
7 mA  
15 mA  
80 mV  
3 mA  
7 mA  
Load Regulation (change in output voltage or current for any load change within ratings)  
Voltage:  
Current:  
1 mV  
2 mA  
2 mV  
1 mA  
3 mV  
0.5 mA  
4 mV  
0.5 mA  
5 mV  
0.5 mA  
Line Regulation (change in output voltage or current for any line change within ratings  
Voltage:  
Current:  
0.5 mV  
2 mA  
0.5 mV  
1 mA  
1 mV  
0.75 mA  
1 mV  
0.5 mA  
2 mV  
0.5 mA  
Transient Response Time (for the output voltage to recover to its previous level (within 0.1% of the rated voltage or  
20 mV, whichever is greater) following any step change in load current up to 50% of the rated current.  
< 100 µs  
AC Input Ratings (selectable via internal switching - see Appendix B)  
Nominal line voltage  
100,120,220,240 Vac:  
230 Vac:  
F requency range:  
-13%, +6 %  
-10%, +10%  
47-63 Hz  
Output Terminal Isolation  
±240 Vdc (maximum, from chassis ground)  
Notes: 1For Supplemental Characteristics, see Table 1-2b.  
General Information 25  
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Table 1-2b. Supplemental Characteristics for Series 665xA1  
Agilent Model Number  
Parameter  
6651A  
6652A  
6653A  
6654A  
6655A  
Output Programming Range (maximum programmable values)  
Voltage:  
Current:  
Overvoltage Protection (OVP):  
8.190 V  
51.188 A  
8.8 V  
20.475 V  
25.594 A  
22.0 V  
35.831 V  
15.356 A  
38.5 V  
61.425 V  
9.214 A  
66.0 V  
122.85 V  
4.095 A  
132.0 V  
Average Resolution  
Voltage:  
Current:  
2 mV  
15 mA  
13 mV  
5 mV  
7 mA  
30 mV  
10 mV  
4 mA  
54 mV  
15 mV  
2.5 mA  
93 mV  
30 mV  
1 mA  
190 mV  
Overvoltage Protection (OVP):  
Accuracy  
Overvoltage Protection (OVP):*  
Analog Programming (VP):*  
160 mV  
6 mV  
400 mV  
15 mV  
31 mA  
400 mA  
700 mV  
27 mV  
16 mA  
120 mA  
1.2 V  
45 mV  
8 mA  
2.4 V  
90 mV  
5 mA  
0.36% +  
Analog Programming (IP):*  
Current Monitor (+IM):*  
*Referenced to supply output  
7% +  
7% +  
75 mA  
730 mA  
80 mA  
75 mA  
Drift Temperature Stability (following a 30-minute warmup, change in output over eight hours under constant line,  
load, and ambient temperature)  
Voltage:  
Current:  
0.02% +  
0.02% +  
0.4 mV  
40 mA  
1 mV  
15 mA  
2 mV  
8 mA  
3 mV  
5 mA  
6 mV  
2.5 mA  
Temperature Coefficients (change per °C)  
Voltage:  
+Current:  
Voltage Readback:  
+Current Readback:  
-Current Readback:  
60 ppm +  
90 ppm +  
60 ppm +  
90 ppm +  
105 ppm +  
0.1 mV  
1.4 mA  
0.2 mV  
1.7 mA  
1.7 mA  
0.2 mV  
0.7 mA  
0.5 mV  
0.9 mA  
0.9 mA  
0.3 mV  
0.3 mA  
0.75 mV  
0.5 mA  
0.5 mA  
0.5 mV  
0.2 mA  
1.3 mV  
0.3 mA  
0.3 mA  
1.1 mV  
0.2 mA  
2.6 mV  
0.2 mA  
0.2 mA  
Overvoltage Protection (OVP):  
200 ppm +  
1.6 mV  
0.1 mV  
1.4 mA  
1.4 mA  
3.3 mV  
0.25 mV  
0.7 mA  
0.7 mA  
5 mV  
13 mV  
0.7 mV  
0.2 mA  
0.2 mA  
24 mV  
1.25 mV  
0.15 mA  
0.15 mA  
Analog Programming (VP):  
Analog Programming (IP):  
Current Monitor (+IM):  
Maximum Input Power  
60 ppm +  
90 ppm +  
80 ppm +  
0.4 mV  
0.3 mA  
0.3 mA  
1380 VA; 1100 W, 120 W with no load  
Notes:  
1For Performance Specifications, see Table 1-2a.  
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Table 1-2b. Supplemental Characteristics for Series 665xA (continued)1  
Parameter  
Agilent Model Number  
6651A  
6652A  
6653A  
6654A  
6655A  
Maximum AC Line Current Ratings  
100 Vac nominal:  
120 Vac nominal:  
220 Vac nominal:  
230 Vac nominal:  
12 A rms (15 AM fuse)  
10 A rms (12 AM fuse)  
5.7 A rms (7 AM fuse)  
5.5 A rms (7 AM fuse)  
5.3 A rms (7 AM fuse)  
240 Vac nominal:  
Maximum Reverse Bias Current:  
With AC input power applied and the dc output reverse  
biased by an external dc source, the supply will continuously  
withstand without damage a current equal to its output  
current rating (see Table 1- 2a) .  
Remote Sensing Capability  
Voltage Drop Per Lead:  
Up to 1/2 of rated output voltage.  
Load Regulation:  
Load Voltage:  
Add 3 mV to spec (see Table l-2a) for each l-volt change in  
the + output lead due to load current changes.  
Subtract voltage drop in load leads from specified output  
voltage rating.  
Command Processing Time (Average time for output voltage to change after receipt of digital data when the supply  
is connected directly to the GPIB Bus):  
20 ms  
Downprogrammer Current Capability (± 15%):  
11.6 A  
5 A  
3 A  
1.8 A  
1.5 A  
Output Voltage Programming Response Time  
Rise/Fall Time (time for output to change from 90 % to 10% or from 10% to 90% of its total excursion):  
<15 ms  
Settling Time (time for output change to settle within 1 LSB (0.025% x rated voltage) of its final value):  
<60 ms  
Monotonicity:  
Output is monotonic over entire rated voltage, current, and  
temperature range.  
Auto-Parallel Configuration:  
Up to 3 identical models  
Analog Programming (IP & VP)  
Input Signal:*  
0 to -5 V  
Input Impedance:  
*Signal source must be isolated.  
10 kΩ, nominal  
Current Monitor Output (+IM):  
0 to -5 V represents zero to full-scale current output.  
Savable States  
Nonvolatile Memory Locations:  
Nonvolatile Memory Write Cycles:  
Prestored State (factory default):  
5 ( 0 through 4)  
40,000, typical  
Location 0  
Notes: lFor Performance Specifications, see Table l-2a.  
General Information 27  
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Table 1-2b. Supplemental Characteristics for Series 665xA (continued)1  
Parameter  
Digital Port Characteristics  
All Models  
(see Table 1-5)  
GPIB Interface Capabilities  
Serial Link Capabilities  
(see Table 1-5)  
(see Table 1-5)  
1 year  
Recommended Calibration Interval:  
Safety Compliance  
Complies with:  
Designed to comply with:  
CSA 22.2 No.231,IEC 348  
UL 1244  
RFI Suppression (complies with):  
CISPR-ll, Group 1, Class B  
Dimensions  
Width:  
425.5 mm (16.75 in)  
132.6 mm (5.22 in)  
497.8 mm (19.6 in)  
Height (including removable feet):  
Depth (including safety cover):  
Weight  
Net:  
Shipping:  
25 kg (54 lb)  
28 kg (61 lb)  
Output Characteristic Curve:  
Notes: lFor Performance Specifications, see Table l-2a.  
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Table 1-2b. Supplemental Characteristics for Series 665xA (continued)1  
Parameter  
All Models  
Output Impedance Curves (Typical):  
Notes: lFor Performance Specifications, see Table l-2a.  
General Information 29  
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Table 1-3a. Performance Specifications for Series 667xA1  
Agilent Model Number  
Parameter  
Output Ratings  
6671A  
6672A  
6673A  
6674A  
6675A  
Voltage:  
Current:@ 0 to 55°C  
0 - 8 V  
0 - 220 A  
0 - 20 V  
0 - 100 A  
0- 35 V  
0 - 60 A  
0 - 60 V  
0 - 35 A  
0 - 120 V  
0 - 18 A  
Programming Accuracy (@ calibration temperature* ± 5 °C)  
Voltage:  
Current:  
0.04% +  
0 . l % +  
8 mV  
20 mV  
60 mA  
35 mV  
40 mA  
60 mV  
25 mA  
120 mV  
12 mA  
125 mA  
Ripple & Noise (from 20 Hz to 20 MHz with outputs ungrounded, or with either output terminal grounded)  
Constant Voltage:  
Constant Voltage:  
Constant Current:  
rms  
p-p  
rms  
1.25 mV  
11 mV  
25 mA  
1.9 mV  
16 mV  
12 mA  
650 µV  
7 mV  
200 mA  
750 µV  
9 mV  
100 mA  
800 µV  
9 mV  
40 mA  
Readback Accuracy (from front panel or over GPIB with respect to actual output @ calibration temp1 ± 5 °C)  
Voltage:  
Current:  
0.05% +  
0.1% +  
12 mV  
30 mV  
50 mV  
60 mA  
90 mV  
35 mA  
180 mV  
18 mA  
150 mA  
100 mA  
Load Regulation (change in output voltage or current for any load change within ratings)  
Voltage:  
Current:  
0.002% +  
0.005% +  
1.2 mV  
4 mA  
2 mV  
2 mA  
4 mV  
1 mA  
300 µV  
10 mA  
650 µV  
7 mA  
Line Regulation (change in output voltage or current for any line change within ratings  
Voltage:  
Current:  
0.002% +  
0.005% +  
1.2 mV  
4 mA  
2 mV  
2 mA  
4 mV  
1 mA  
bisep>  
300 µV  
10 mA  
650 µV  
7 mA  
Transient Response Time (for the output voltage to recover to its previous level (within 0.1% of the rated voltage or  
20 mV, whichever is greater) following any step change in load current up to 50% of the rated current.  
< 900 µs  
AC Input Ratings (selectable via internal switching - see Appendix B)  
Nominal line voltage  
200 Vac:*  
*below 185 Vac, derate output voltage  
linearly to :  
174-220 Vac  
31.5 V  
7.8 V  
18.0 V  
56.5 V  
108 V  
230 Vac:  
F requency range:  
191-250 Vac  
47-63 Hz  
Output Terminal Isolation  
±240 Vdc (maximum, from chassis ground)  
Notes: 1For Supplemental Characteristics, see Table 1-3b.  
30 General Information  
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Table 1-3b. Supplemental Characteristics for Series 667xA1  
Agilent Model Number  
Parameter  
6671A  
6672A  
6673A  
6674A  
6675A  
Output Programming Range (maximum programmable values)  
Voltage:  
Current:  
Overvoltage Protection (OVP):  
8.190 V  
225.23 A  
10.0 V  
20.475 V  
102.37 A  
24.0 V  
35.831 V  
61.43 A  
42.0 V  
61.425 V  
35.83 A  
72.0 V  
122.85 V  
18.43 A  
144.0 V  
Typical Resolution  
Voltage:  
Current:  
2 mV  
55 mA  
15 mV  
5 mV  
25 mA  
35 mV  
10 mV  
15 mA  
65 mV  
15 mV  
8.75 mA  
100 mV  
30 mV  
4.5 mA  
215 mV  
Overvoltage Protection (OVP):  
Accuracy ( @ calibration temp ±5 °C)*  
Overvoltage Protection (OVP):*  
Analog Programming (VP):  
Analog Programming (IP):  
Current Monitor (+IM):  
200 mV  
500 mV  
900 mV  
± 0.3%  
± 7%  
1.15 V  
3.0 V  
±7%  
*Calibration temp = 25° C  
Drift Temperature Stability (following a 30-minute warmup, change in output over eight hours under constant line,  
load, and ambient temperature)  
Voltage:  
Current:  
0.02% +  
0.02% +  
0.24 mV  
69 mA  
0.6 mV  
35 mA  
1 mV  
20 mA  
1.8 mV  
10 mA  
3.6 mV  
6 mA  
Temperature Coefficients (change per °C after 30-minute warmup)  
Voltage:  
Current:  
Voltage Readback:  
±Current Readback:  
50 ppm +  
75 ppm +  
60 ppm +  
85 ppm +  
0.04 mV  
25 mA  
0.1 mV  
30 mA  
0.2 mV  
12 mA  
0.3 mV  
15 mA  
0.7 mV  
7 mA  
1 mV  
9 mA  
1.2 mV  
4 mA  
1.2 mV  
5 mA  
2.4 mV  
2 mA  
3 mV  
2.5 mA  
Overvoltage Protection (OVP):  
200 ppm +  
Analog Programming (VP):  
1.8 mV  
0.1 mV  
26 mA  
3 mA  
5 mV  
0.3 mV  
14 mA  
2 mA  
8 mV  
0.5 mV  
9 mA  
13 mV  
0.7 mV  
5 mA  
25 mV  
1.5 mV  
3 mA  
60 ppm +  
Analog Programming (±IP):  
275 ppm +  
Current Monitor (+IM):  
50 ppm +  
1 mA  
0.6 mA  
0.3 mA  
Maximum Input VA and Power  
3800 VA; 2600 W, 100 W with no load  
Maximum AC Line Current Ratings  
200 Vac  
19 A rms (25 AM fuse)  
nominal:  
230 Vac  
19 A rms (25 AM fuse)  
nominal:  
Maximum Reverse Bias Current:  
With AC input power applied and the dc output reverse biased by an  
external dc source, the supply will continuously withstand without damage a  
current equal to its output current rating (see Table 1-3a).  
Notes:  
1For Performance Specifications, see Table 1-3a.  
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Table 1-3b. Supplemental Characteristics for Series 667xA (continued)1  
Parameter Agilent Model Number  
6672A 6673A 6674A  
6671A  
6675A  
Remote Sensing Capability  
Voltage Drop Per Lead:  
Load Voltage:  
Up to 1/2 of rated output voltage.  
Subtract voltage drop in load leads from specified output  
voltage rating.  
Load Regulation:  
Degradation due to load lead drop in--output:  
Degradation due to load lead drop in + output:  
∆mV (regulation) = Vdrop(Rsense- )/k  
∆mV (regulation) = Vdrop(Rsense +)/k + 2Vdrop(Vrating)/(Vrating + 10 V)  
where Rsense - and Rsense + are resistances of respective sense leads and k is the following model-dependent  
value:  
6671A=1; 6672A=1.82; 6673A=4.99; 6674A=10; 6675A=16.2  
Command Processing Time (Average time for output voltage to change after receipt of digital data when the supply  
is connected directly to the GPIB Bus):  
20 ms  
Output Voltage Programming Response Time**  
Rise/Fall Time (time for output to change from 90 % to 10% or from 10% to 90% of its total excursion):***  
30 ms  
60 ms  
130 ms  
130 ms  
195 ms  
600 ms  
Full-load programming speed up/down time (time for output to settle within 4 LSBs of the final value):***  
85 ms  
190 ms  
380 ms  
380 ms  
No-load downprogrammiug discharge time (time for output to fall to 0.5 V when programmed from full voltage to  
zero volts):  
130 ms  
250 ms  
350 ms  
600 ms  
600 ms  
** All values exclude command processing time.  
*** With full resistive load = VRATED/IRATED.  
Monotonicity:  
Output is monotonic over entire rated voltage, current, and  
temperature range.  
Auto-Parallel Configuration:  
Up to 3 identical models  
Analog Programming (IP & VP)  
Input Signal:*  
VP Input Signal:**  
VP Input Impedance:  
(0 to )  
(0 to )  
-4.72 V  
+7.79 V  
-4.24 V  
+6.81 V  
-4.25 V  
60 kΩ, nominal  
+6.81 V  
-4.24 V  
=7.01 V  
-3.97 V  
+6.34 V  
IP to -IP Differential Input Signal:  
*Signal source must be isolated.  
** Referenced to output signal common.  
Current Monitor Output (+IM):  
Output Signal:*  
(-0.25 to )  
+9.05 V  
+7.70 V  
+7.70 V  
+7.93 v  
+7.15 V  
Output Impedance:  
490 Ω  
* Corresponds to 0% to 100% output current.  
Savable States  
Nonvolatile Memory Locations:  
Nonvolatile Memory Write Cycles:  
Prestored State (factory default):  
5 ( 0 through 4)  
40,000, typical  
Location 0  
Notes: lFor Performance Specifications, see Table l-3a.  
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Table 1-3b. Supplemental Characteristics for Series 667xA (continued)1  
Parameter  
Digital Port Characteristics  
All Models  
(see Table 1-5)  
GPIB Interface Capabilities  
Serial Link Capabilities  
(see Table 1-5)  
(see Table 1-5)  
1 year  
Recommended Calibration Interval:  
Safety Compliance  
Complies with:  
Designed to comply with:  
CSA 22.2 No.231,IEC 348  
UL 1244  
RFI Suppression (complies with):  
CISPR-ll, Group 1, Class B  
Dimensions  
Width:  
425.5 mm (16.75 in)  
145.1 mm (5.71 in)  
640 mm (25.2 in)  
Height (including removable feet):  
Depth (including safety cover):  
Weight  
Net:  
Shipping:  
27.7 kg (61 lb)  
31.4 kg (69 lb)  
Output Characteristic Curve:  
Notes: lFor Performance Specifications, see Table l-3a.  
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Table 1-3b. Supplemental Characteristics for Series 667xA (continued)1  
Parameter  
All Models  
Output Impedance Curves (Typical):  
Notes: lFor Performance Specifications, see Table l-3a.  
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Table 1-4a. Performance Specifications for Series 668xA1  
Agilent Model Number  
Parameter  
Output Ratings  
6680A  
6681A  
6682A  
6683A  
6684A  
Voltage:  
0 - 5 V  
0 - 8 V  
0- 21 V  
0 - 32 V  
0 - 40 V  
Current:*  
0 - 875 A  
0 - 580 A  
0 - 240 A  
0 - 160 A  
0 - 128 A  
*Derated linearly 1%/°C from 40 ° C to 55 °C  
Programming Accuracy (@ 25 ± 5 °C)  
Voltage:  
Current:  
0.04% +  
0 . l % +  
5 mV  
8 mV  
21 mV  
32 mV  
85 mA  
40 mV  
65 mA  
450 mA  
300 mA  
125 mA  
Ripple & Noise (from 20 Hz to 20 MHz with outputs ungrounded, or with either output terminal grounded)  
Constant Voltage:  
Constant Voltage:  
Constant Current:**  
rms  
p-p  
rms  
1.5 mV  
10 mV  
290 mA  
1.5 mV  
10 mV  
190 mA  
1.0 mV  
10 mV  
40 mA  
1.0 mV  
10 mV  
28 mA  
1.0 mV  
10 mV  
23 mA  
**With load inductance > 5µH.  
Readback Accuracy (from front panel or over GPIB with respect to actual output @ 25 ± 5 °C)  
Voltage:  
0.05% +  
0.1% +  
7.5 mV  
600 mA  
12 mV  
32 mV  
48 mV  
110 mA  
60 mV  
90 mA  
400 mA  
165 mA  
±Current  
Load Regulation (change in output voltage or current for any load change within ratings)  
Voltage  
Current:  
0.002% +  
0.005% +  
1.1 mV  
12 mA  
1.5 mV  
9 mA  
190 µV  
65 mA  
300 µV  
40 mA  
650 µV  
17 mA  
Line Regulation (change in output voltage or current for any line change within ratings)  
Voltage:  
Current:  
0.002% +  
0.005% +  
1.1 mV  
12 mA  
1.5 mV  
9 mA  
190 µV  
65 mA  
300 µV  
40 mA  
650 µV  
17 mA  
Transient Response Time (for the output voltage to recover to within 150 mV following any step change from 100% to  
50% or 50% to 100% of the rated output current): < 900 µs  
AC Line Input * (selectable - see Appendix C)  
Range 1  
Ac input phase-to-phase voltage:  
Ac input frequency:  
3-phase 180-235 Vac  
47-63 Hz *  
Range 2  
Ac input phase-to-phase voltage:  
Ac input frequency:  
3-phase 360-440 Vac  
47-63 Hz *  
* Power source can be DELTA or WYE.  
* For 47 to 53 on Range 1 only, derate output voltage linearly from 100% at 200 Vac to 95% at 180 Vac.  
Notes: 1For Supplemental Characteristics, see Table 1-4b.  
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Table 1-4b. Supplemental Characteristics for Series 668xA1  
Agilent Model Number  
Parameter  
6680A  
6681A  
6682A  
6683A  
6684A  
Output Programming Range (maximum programmable values)  
Voltage:  
Current:  
Overvoltage Protection (OVP):  
5.125 V  
895 A  
6.25 V  
8.190 V  
592 A  
10.0 V  
21.50 V  
246 A  
25.2 V  
32.75 V  
164 A  
38.4 V  
41.0 V  
131 A  
48.0 V  
Typical Resolution  
Voltage:  
Current:  
1.35 mV  
235 mA  
30 mV  
2.15 mV  
155 mA  
45 mV  
5.7 mV  
64 mA  
120 mV  
8.6 mV  
43 mA  
180 mV  
10.8 mV  
34 mA  
225 mV  
Overvoltage Protection (OVP):  
Accuracy ( @ 25 ±5 °C)*  
Overvoltage Protection (OVP):  
Analog Programming (VP): ±0.3%±  
Analog Programming (IP):±2% ±  
Current Monitor (IM):±2%±  
Analog Programming (VP & IP)  
Input Signal (source must be isolated)  
VP Input Signal:*  
120 mV  
10 mV  
8 A  
180 mV  
20 mV  
4 A  
470 mV  
50 mV  
2 A  
720 V  
75 mV  
1.5 A  
900 V  
100 mV  
1 A  
8 A  
4 A  
2 A  
1.5 A  
1 A  
0 to -5.0 V  
+ IP Input Signal:**  
0 to +5.0 V  
Input Impedance  
VP and IP Inputs:  
*Referenced to common P.  
Current Monitor (IM) Output Signal:  
> 30 kΩ  
** Referenced to -IP differential input signal  
-0.125 V to +5 V  
↓
Drift Temperature Stability (following a 30-minute warmup, change in output over eight hours under constant line,  
load, and ambient temperature)  
Voltage:  
Current:  
0.02% +  
0.02% +  
0.15 mV  
315 mA  
0.24 mV  
170 mA  
0.63 mV  
71 mA  
0.96 mV  
47 mA  
1.2 mV  
38 mA  
Temperature Coefficients (change per °C after 30-minute warmup)  
Voltage:  
Current:  
Voltage Readback:  
±Current Readback:  
50 ppm +  
75 ppm +  
60 ppm +  
85 ppm +  
0.05 mV  
110 mA  
0.075 mV  
135 mA  
0.08 mV  
62 mA  
0.1 mV  
90 mA  
0.21 mV  
26 mA  
0.25 mV  
37 mA  
0.32 mV  
17 mA  
0.40 mV  
25 mA  
0.40 mV  
14 mA  
0.50 mV  
20 mA  
Overvoltage Protection (OVP):  
200 ppm +  
1.25 mV  
1.8 mV  
4.7 mV  
7.2 mV  
9.0 mV  
Typical Common Mode Noise Current*  
rms:  
peak-to-peak:  
1.5 mA  
10 mA  
1.5 mA  
10 mA  
3 mA  
20 mA  
3 mA  
20 mA  
3 mA  
20 mA  
* Referenced to signal ground binding post.  
Output Float Voltage (maximum from output signal ground):  
Notes:  
±60 Vdc  
1For Performance Specifications, see Table 1-4a.  
36 General Information  
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Table 1-4b. Supplemental Characteristics for Series 668xA (continued)1  
Parameter Agilent Model Number  
6681A 6682A 6683A  
6680A  
6684A  
Remote Sensing Capability  
Voltage Drop Per Lead:  
Up to 1/2 of rated output voltage.  
Load Voltage:  
Subtract voltage drop in load leads from specified output  
voltage rating.  
Load Regulation:  
Degradation due to load lead drop in--output:  
Degradation due to load lead drop in + output:  
∆mV (regulation) = Vdrop(Rsense -)  
∆mV (regulation) = Vdrop(Rsense +) + 2Vdrop(Vrating)/(Vrating + 10 V)  
where Rsense _ and Rsense + are resistances of respective sense leads.  
Maximum Reverse Voltage Current Sink Capability: *  
·
With ac input power applied and the dc output reverse biased  
by an external dc source, the supply will continuously  
withstand without damage a current equal to its output  
current rating.  
* Current must be limited by user's external dc source.  
Typical Common Mode Noise Current **  
rms:  
1.5 mA  
Peak-to-Peak  
Load Voltage:  
10 mA  
Subtract voltage drop in load leads from specified output  
voltage rating.  
** From 20 Hz to 2 MHz, referenced to signal ground binding post.  
Maximum Input Power:  
7350 VA, 6000 W, 160 W with no load  
Maximum AC Line Current Ratings  
Range 1  
Rms line current:  
Line fuse:  
21.4 A (27.7 A) ***  
30 AM  
Range 2  
Rms line current:  
Line fuse:  
10.7 A (14.4 A) ***  
16 AM  
*** Includes 5% unbalanced voltage phase condition.  
Output Voltage Programming Response Time**  
Programming Rise/Fall Time (time for output to change from 90 % to 10% or from 10% to 90% of its total  
excursion):***  
9 ms  
12 ms  
45 ms  
60 ms  
60 ms  
Full-load programming speed up/down time (time for output to settle within 4 LSBs of the final value):***  
27 ms  
35 ms  
140 ms  
185 ms  
185 ms  
No-load downprogrammiug discharge time (time for output to fall to 0.5 V when programmed from full voltage to  
zero volts):  
90 ms  
100 ms  
475 ms  
650 ms  
575 ms  
** All values exclude command processing time.  
*** With full resistive load = VRATED/IRATED  
Notes: lFor Performance Specifications, see Table l-4a.  
General Information 37  
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Table 1-4b. Supplemental Characteristics for Series 668xA (continued)1  
Parameter All Models  
Command Processing Time (Average time for output voltage to change after receipt of digital data when the supply is  
connected directly to the GPIB Bus): 20 ms  
Monotonicity:  
Output is monotonic over entire rated voltage, current, and  
temperature range.  
Auto-Parallel Configuration:  
Up to 3 identical models  
Nonvolatile Storage  
State storage & recall locations:  
Prestored turn-on state:  
Maximum memory write cycles:  
4
Location 0  
40,000, typical  
Digital Port Characteristics  
GPIB Interface Capabilities  
Serial Link Capabilities  
(see Table 1-5)  
(see Table 1-5)  
(see Table 1-5)  
1 year  
Recommended Calibration Interval:  
Safety Compliance  
Complies with:  
Designed to comply with:  
CSA 22.2 No.231,  
IEC 1010 (carries CE mark)  
UL 1244  
RFI Suppression (complies with):  
Dimensions  
CISPR-ll, Group 1, Class B  
Width:  
425.5 mm (16.75 in)  
Height  
including removable feet  
excluding removable feet  
Depth (without output safety cover):  
234.2 mm (9.25 in)  
221.5 mm (8.75 in)  
674.7 mm (25.56 in)  
Weight  
Net:  
Shipping:  
51.3 kg (113 lb)  
63.6 kg (140 lb)  
Output Characteristic Curve:  
Notes: lFor Performance Specifications, see Table l-4a.  
38 General Information  
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Table 1-4b. Supplemental Characteristics for Series 668xA (continued)1  
Parameter  
All Models  
Output Impedance Curves (Typical):  
CV MODE  
CC MODE  
CV MODE  
CC MODE  
*
20  
20  
10  
5
*
10  
5
**  
**  
2.5  
2.5  
1.25  
1.25  
0.625  
0.625  
0.312  
0.156  
0.312  
0.156  
0.078  
0.078  
0.039  
0.039  
0.195  
0.0195  
1K  
30  
100  
10K  
50K  
50K  
100  
10K  
1K  
30  
FREQUENCY (HZ)  
FREQUENCY (HZ)  
Agilent 6681A  
Agilent 6680A  
CV MODE  
CC MODE  
CV MODE  
CC MODE  
*
*
4040  
20  
80  
**  
**  
40  
10  
20  
5
10  
5
2.5  
1.25  
2.5  
0.625  
0.312  
0.156  
1.25  
0.625  
0.312  
0.0781  
0.0391  
0.156  
0.0781  
30  
100  
1K  
10K  
50K  
30  
100  
1K  
10K  
50K  
FREQUENCY (HZ)  
FREQUENCY (HZ)  
Agilent 6682A  
Agilent 6683A  
CV MODE  
CC MODE  
**  
*
80  
* ALL COMPENSATION SWITCHES OPEN  
** ALL COMPENSATION SWITCHES CLOSED  
40  
20  
10  
5
2.5  
1.25  
O.625  
O.312  
0.156  
0.0781  
30  
100  
1K  
10K  
50K  
FREQUENCY ( HZ )  
Agilent 6684A  
Notes: lFor Performance Specifications, see Table l-4a.  
General Information 39  
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Table 1-5. Supplemental GPIB Characteristics For All Models  
Parameter  
All Models  
Digital Port Characteristics  
Maximum ratings:  
16.5 Vdc between terminals 1 & 2; 3 & 4; and from 1 or 2 to  
chassis ground  
FLT/INH Operation  
FLT/INH Terminals 1 & 2  
Iol (low-level output current)  
Vol (low-level output voltage)  
FLT/INH Terminals 3 & 4  
V il (low-level input voltage)  
V ih (high-level input voltage)  
I il (low-level input current)  
tw (pulse width)  
1.25 mA maximum  
0.5 V maximum  
0.8 V maximum  
2.0 V minimum  
1 mA  
100 µs, minimum  
4 ms, typical  
td (time delay)  
Digital I/O Operation  
Digital OUT Port 0,1,2 - Open Collector:  
I oh (high-level output leakage @ 16.5 V)  
100 µA (ports 0,1); 12.5 mA (port 2)  
I
oh (high-level output leakage @ 5.25 V)  
100 µA (ports 0,1); 250 µA (port 2)  
I ol (low-level output sink current @ 0.5 V)  
I ol (low-level output sink current @ l V)  
4 mA  
250 mA  
Digital IN Port 2 - Internal 4.64 k Pullup:  
I il (low-level input current @ 0.4 V)  
I ih (high-level input current @ 5.25 V)  
V il (low-level input voltage)  
1.25 mA  
250 µA  
0.8 V maximum  
2.0 V minimum  
Vih (high-level input voltage)  
GPIB Interface Capabilities  
Languages:  
Interface:  
SCPI (default); Compatibility  
AH1, C0, DC1, DT1, E1, LE4, PP0, RL1, SH1,  
SR1, TE6  
Serial Link Capabilities (multiple supplies sharing one GPIB primary address)  
Maximum number of supplies:  
16  
15  
Maximum number of linked supplies:  
Maximum total chain cable length:  
30 m (100 ft)  
40 General Information  
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Table 1-6. Operator Replaceable Parts List  
Description  
Agilent Part No.  
(Unless otherwise specified, parts apply to all models.)  
Cable assembly, GPIB  
Cable assembly, serial link  
Collar, rotary output control  
Cover, ac input safety  
(See “Accessories”)  
(See “Accessories”)  
5040-l700  
Series 667xA, w/strain relief connector & rubber boot  
Series 668xA  
5040- 1676  
5060-3237  
Cover, dc output  
Series 664xA and 665xA  
Series 667xA  
Series 668xA  
Flatwasher, ac input safety cover (Series 667xA and 668xA)  
Foot, cabinet  
0360-2191  
5040- 1674  
5060- 1692  
3050-1053  
5041-8801  
Fuse, power  
Series 664xA  
100 Vac line voltage, 6 AM  
120 Vac line voltage, 5 AM  
220/230/240 Vac line voltage, 3 AM  
Series 665xA  
2110-0056  
2110-0010  
2l10-0003  
100 Vac line voltage, 15 AM  
120 Vac line voltage, 12 AM  
220/230/240 Vac line voltage, 7 AM  
Series 667xA*  
2110-0054  
2110-0249  
21l0-06l4  
*This is an internal fuse not replaceable by the operator.  
Series 668xA  
30 AM for 180-235 Vac line (set of 3)  
16 AM for 360-440 Vac line (set of 3)  
Knob, rotary output control  
Lockwasher, ac input safety cover (Series 667xA and 668xA)  
Lockwasher, output bus bar, 1/4 spring (Series 667xA only)  
Manual  
5060-3513  
5060-3512  
0370-1091  
2190-0484  
3050-1690  
Agilent 59510A/11 Relay Accessories  
Series 603xA Operating  
Series 664xA and 665xA Service  
Series 664xA, 665xA, 667xA and 668xA Programming Guide  
Series 667xA Service  
Nut, output bus bar, hex 1/4-20x1/2 (Series 667xA only)  
Nut, power ground, hex w/lw 3/8x32  
Nut, power input cable (Series 668xA only)  
Plug, analog connector  
Plug, digital connector  
Power cord assembly  
Rack mount kit  
Resistor, calibration  
5957-6382  
5959-3301  
5959-3376  
5960-5597  
5959-3384  
2950-0084  
0590-0305  
0535-0082  
1252-3698  
1252-1488  
(See "Options" )  
(See "Options")  
(See Appendix A)  
0515-0156  
0515-1384  
0360-219l  
Screw, ac input safety cover, M4.0 x 60 mm long (Series 667xA and 668xA)  
Screw, carrying strap, M5x0.8x10 mm  
Screw, dc output cover (Series 664xA and 665xA)  
General Information 41  
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Table 1-6. Operator Replaceable Parts List (continued)  
Description  
Agilent Part No.  
(Unless otherwise specified, parts apply to all models.)  
Screw, output bus bar  
Series 665xA only  
0515-1085  
Series 667xA only, 1/4-20x1/2  
Screw, outer cover, M5 x 0.8 mm  
Screw, output sense terminal, M3x0.5x8mm  
Slide mount kit  
2940-0103  
0515-0073  
0515-0104  
( “See Accessories” )  
0380-0643  
Standoff, GPIB  
Terminal, crimp, ac power cord (Series 667xA only)  
L or N terminal  
Gnd terminal  
0362-0681  
0362-0207  
42 General Information  
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2
Installation  
Inspection  
Damage  
When you receive your power supply, inspect it for any obvious damage that may have occurred during shipment. If there is  
damage, notify the shipping carrier and the nearest Agilent Sales and Support Office immediately. Warranty information is  
printed in the front of this guide.  
Packaging Material  
Until you have checked out the power supply save the shipping carton and packing materials in case the power supply has to  
be returned to Agilent Technologies. If you return the power supply for service, attach a tag identifying the model number  
and the owner. Also include a brief description of the problem.  
Note  
Series 668xA Only  
When you no longer need the shipping carton and packing materials, package and return them to the  
recycle center that has been provided for you. In most cases, you may do this free of any shipping charges.  
Please follow the instructions in the pack return system that was included with your power supply.  
Items Supplied  
In addition to this manual, check that the following items in Table 2-1 are included with your power supply (see Table 1-6  
for part numbers):  
Table 2-1. Items Supplied  
Power cord  
Series 664xA and 665xA  
Your power supply was shipped with a power cord for the type of outlet specified for your location. If  
the appropriate cord was not included, contact your nearest Agilent Sales and Support Offices (see end  
of this guide) to obtain the correct cord. Caution: Your power supply cannot use a standard power cord.  
The power cords supplied by Agilent Technologies have heavier gauge wire.  
Series 667xA and 668xA  
Your power supply was shipped with a power cord appropriate for your location. The cord may or may  
not be terminated in a power plug (see "Options" in Chapter 1). If the cord is not included, contact your  
nearest Agilent Sales and Support Office (see end of this guide ) to obtain the correct cord. These  
models also include a power input safety cover with strain relief connector. It is required to secure the  
power cord to the power supply.  
Analog  
connector  
A 7-terminal analog plug (see Table 1-6) that connects to the back of the supply. Analog connections are  
described in Chapter 4.  
Digital  
connector  
A 4-terminal digital plug (see Table 1-6) that connects to the back of the supply. Digital connections are  
described in "Appendix D - Digital Port Functions"  
Serial cable  
A 2-meter cable (see “Accessories” in Chapter 1) that connects to the control bus (next to the GPIB  
connector). This cable is used to serially connect multiple supplies as described under "Controller  
Connections" in Chapter 4.  
Installation 43  
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Table 2-1. Items Supplied (continued)  
Output  
Series 667xA only  
hardware  
Output hardware (screws with nuts and lockwashers) for securing your load wires to the output bus bars  
(see Table 1-6).  
Pack return  
system  
Series 668xA Only  
(Agilent P/N 5080-2430). Materials and instructions for properly disposing of the shipping carton and  
packing materials.  
Guide change  
page  
If applicable, change sheets may be included with this guide. If there are change sheets, make the  
indicated corrections in this guide.  
Location and Temperature  
Bench Operation  
The “Supplemental Characteristics” in Chapter 1 give the dimensions of your power supply. The cabinet has plastic feet that  
are shaped to ensure self-alignment when stacked with other Agilent System II cabinets. The feet may be removed for rack  
mounting. Your power supply must be installed in a location that allows sufficient space at the sides and rear of the cabinet  
for adequate air circulation. Minimum clearances are 1 inch (25 mm) along the sides. Do not block the fan exhaust at the  
rear of the supply.  
Rack Mounting  
Series 668xA supplies weigh 51.3 kg (113 lb). Obtain adequate help when mounting the supply in the  
rack.  
The power supply can be mounted in a standard l9-inch rack panel or cabinet. Rack mounting kits are available as Option  
908 or 909 (with handles). Installation instructions are included with each rack mounting kit.  
Series 667xA & 668xA  
Series 667xA and 668xA supplies require instrument support rails for non-stationary installations.  
These are normally ordered with the cabinet and are not included with the rack mounting kits.  
Temperature Performance  
A variable-speed fan cools the supply by drawing air through the sides and exhausting it out the back. Using Agilent rack  
mount or slides will not impede the flow of air. The temperature performance is as follows:  
Series 664xA & 665xA Operates without loss of performance within the temperature range of 0 °C to 40 °C and with  
derated output from 40 °C to 55 °C.  
Series 667xA & 668xA Operates without loss of performance within the temperature range of 0 °C to 55 °C.  
It a Series 664xA or 665xA power supply is operated at full output current for several hours, the sheet  
metal immediately under the transformer (near the right front) can get very hot. Do not touch this area of  
the cabinet. The line cord also can become quite warm. Both of these conditions are normal.  
44 Installation  
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INPUT POWER SOURCE  
Refer to the applicable paragraphs below for information on the input power source. Do not apply power to the power  
supply until directed to do so in Chapter 3.  
Check the line  
label on the rear of your supply and verify that the voltage shown there  
corresponds to the nominal line voltage of your power source. If it does not, see "Appendix C - Line  
Voltage Conversion" for instructions on changing the power supply’s line voltage configuration.  
Series 664xA and 665xA Supplies  
The supplied cord connects to the power receptacle on the rear panel ( 2, Figure 2-l).  
■
You can operate your supply from a nominal l00 V, 120 V, 220 V, 230 V, or 240 V single-phase ac power source as  
indicated on the rear panel line label 1.  
■
■
See "AC Input Ratings" in Table l-la or Table 1-2a for the voltage and frequency range for each type of power source.  
"Maximum AC Line Current Ratings" in Table l-lb or Table 1-2b show the maximum load current.  
The line fuse is located in a fuseholder on the rear panel . The rear panel label 1 shows the fuse value used in the  
3
power supply and Table 1-6 identifies the replacement fuse.  
Figure 2-1. Series 664xA and 665xA Power Connection  
Series 667xA Supplies  
Note  
This product requires single-phase input voltage.  
You can operate your supply from a nominal 200 V or 230 V, single-phase power source, or from the line-to-line voltage of  
a 208-volt, 3-phase source. The proper source is indicated on the rear  
label ( 4, Figure 2-2). See "AC Input  
Ratings" in Table 1-3a for the voltage and frequency range for each type of power source.  
Note  
The power source must be a dedicated line with no other devices drawing current from it.  
The line fuse is located inside the power supply. Table 1-6 identifies the replacement fuse. See "In Case of Trouble" in  
Chapter 3 for instructions on fuse replacement.  
Installation 45  
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Installing the Power Cord  
Installation of the power cord must be done by a qualified electrician and in accordance with local  
electrical codes.  
The power cord supplied with power supply may or may not include a power plug (see "Options" in Chapter l) at one end of  
the cord. Terminating connections and a ground lug are attached to the other end of the cord.  
See Figure 2-2 and proceed as follows:  
1. If they are not already in place, position the strain relief connector  
connector nut on the power cord  
2. Secure the ground wire to the chassis earth ground stud.  
), safety cover , rubber boot , and  
.
3. For single-phase operation, connect the neutral wire to the N input terminal and the line wire to the L input  
terminal (this line is fused inside the supply).  
4. For line-to-line operation from a three-phase source as shown in Figure 2-3, connect one phase to the N input  
terminal and another phase to the L input terminal (this line is fused inside the supply).  
Note  
The N terminal is not internally grounded.  
5. Position the safety cover over the power input terminals and tighten the cover screws  
and strain relief connector  
screws  
.
Figure 2-2. Connecting the Series 667xA Power Cord  
46 Installation  
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Figure 2-3. 667xA Connection to a 3-Phase Line  
Series 668xA Supplies  
Line Wiring  
The power supply requires a 3-phase power source that provides 7350 VA (6000 W) maximum. The power supply has a  
delta input (no neutral connection) and will accept power from either delta (triangle) or wye (star) sources. Two voltage  
ranges are available (see "AC Input Ratings" in Table 1-4a). In order to maintain phase current balancing, the power  
source should be a dedicated line with only Agilent Technologies Series 668xA supplies drawing current from it . A  
disconnect box located near the power supply (see Figure 2-4) is recommended for all installations and is mandatory for  
direct-wired installations.  
€ 3-phase Mains (delta or wye)  
ó AC Safety Disconnect (required for direct-wired installations  
ì Series 668xA Power Supply  
Figure 2-4. Series 668xA Overall Wiring Diagram.  
Installation 47  
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Installing the Power Cord  
Installation of the power cord must be done by a qualified electrician and in accordance with local  
electrical code  
The power cords supplied with the power supply do not include a power plug (see "Options" in Chapter l) at one end of the  
cord. Terminating connectors and a ground lug are attached to the other end of the cord.  
See Figure 2-5 and proceed as follows:  
l. Check the line fuses ( , Figure 2-5) as follows:  
a. Examine the  
label on the rear panel.  
b. Unscrew the line fuse caps ( from the rear panel and verify that all fuses are as specified on the label. Replace the  
fuses.  
2. Open the line clamp and insert the line cord  
through the opening.  
3. Position the line cord so that the clamp is near the end of the outside insulating sheath. Tighten the screws securing  
the clamp.  
4. Secure the three ac lines to the ac power strip as follows:  
*Phase 1 to L1.  
Phase 2 to L2. Phase 3 to L3.  
5. Secure the ground wire to the chassis earth ground stud.  
Do not connect anything to the terminal marked "DO NOT USE".  
6. Slip the safety cover over the fuses and terminal strip and secure the cover with the four capscrews.  
7. If required, wire the appropriate power plug to the other end of the power cord.  
Note  
For user-made cable , strip back sheath 100 mm (3.9 in).  
Figure 2-5. Connecting the Series 668xA Power Cord  
48 Installation  
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3
Turn-On Checkout  
Note  
This chapter provides a preliminary introduction to the power supply front panel. See "Chapter 5 - Front  
Panel" for more details.  
Introduction  
Successful tests in this chapter provide a high degree of confidence that the power supply is operating properly. For  
verification tests, see “Appendix B - Operation Verification”. Complete performance tests are given in the service manual  
(see Table 1-5 in Chapter 1). Do not apply ac power to the power supply until told to do so.  
Preliminary Checkout (All Models)  
1. Make certain that the front panel switch is off.  
2. Examine the Line Voltage Rating or Line And Fuse Rating label (see "Chapter 2 - Installation" )  
a. Verify that the line voltage rating agrees with your power source. If it does not, see "Appendix C - Line Voltage  
Conversion".  
b. Series 664xA/665xA - Use a screwdriver to remove the line fuse from the fuseholder (3, Figure 2-1). Verify that  
the fuse is as specified on the label. Replace the fuse.  
c. Series 668xA - Unscrew the fuse caps from the rear panel (2, Figure 2-4). Verify that the fuse is as specified on  
the label. Replace the fuse.  
3. Check the sense wiring as follows:  
a. Series 664xA/665xA - The SENSE switch (4, Figure 4-3a) is set to Local.  
b. Series 667xA - Remove the output safety cover (1, Figure 4-4a) and examine the output sense terminals (4 and  
5). They should be wired for local sensing as follows:  
1. The +LS sense terminal wired to the +S terminal of the analog connector (2).  
2. The -LS sense terminal wired to the -S terminal of the analog connector.  
3. If the power supply is not wired for local sensing, make the above connections, using small-capacity wire  
(#22 is sufficient).  
c. Series 668xA - Examine the output bus bars (Figure 4-5a) and make sure they are connected for local sensing as  
follows:  
1. The + bar is wired to the +S terminal of the analog connector.  
2. The - bar is wired to the -S terminal of the analog connector.  
3. If the power supply is not wired for local sensing, make the above connections, using small-capacity wire  
(#22 is sufficient).  
4. Make sure that there is no load connected to the output terminals or bus bars.  
Turn-On Checkout 49  
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Power-On Checkout (All Models)  
1. Connect the power cord to the power source (for Series 668xA, turn on the safety disconnect switch).  
2. Turn the front panel power switch to ON (1).  
3. For Series 668xA only, the Check Fuses and Dew LEDs should remain off. If either light is on or is blinking, go to  
“In Case of Trouble” at the end of this chapter.  
4. The power supply undergoes a self-test when you turn it on. If the test is normal, the following sequence appears on  
the LCD:  
a. Series 664xA/665xA - The GPIB address (factory default is 5).  
b. Series 667xA/668xA - The GPIB address (factory default is 5). This is then followed by PWR ON INIT for  
approximately 10 seconds.  
5. The display then goes into the meter mode with the Dis annunciator on and all others off. “Meter mode” means that  
the VOLTS digits indicate the output voltage and the AMPS digits indicate the output current. These values will be at or  
near zero.  
6. Verify that the power supply fan is on by placing your hand near the rear grill to feel the air flow. You may also be  
able to hear the fan operating.  
7. Press  
once. The Dis annunciator will go off and the CV annunciator will go on .  
Note  
If the power supply detects an error during self-test, the display will show an error message. Go to “In  
Case of Trouble” at the end of this chapter.  
Using The Keypad (All Models)  
Shifted Keys  
Some of the front panel keys perform two functions, one labeled in black and the other in blue. You access the blue function  
by first pressing the blue  
key, which is not labeled. When the Shift annunciator is on, you will know you have access  
to the key's shifted (blue) function.  
Backspace Key  
The  
key is an erase key. If you make a mistake entering a number and have not yet entered it (have not pressed  
), you can delete the number by pressing . You may delete as many numbers as you wish by repeatedly pressing  
this key.  
Output Checkout (All Models)  
Important  
When the power supply is turned on, it asserts the state stored in EEPROM memory location 0.  
For a new supply, this is the factory default (*RST) state. The following procedures assume that the  
factory default state is still in location 0 (Turn-On Conditions in “Chapter 5 - Front Panel” for details).  
50 Turn-On Checkout  
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Checking the Voltage Function (All Models)  
The tests in Table 3-1 check the basic voltage functions with no load connected to the power supply. The VOLTS display  
will show various readings. Ignore the AMPS display.  
Table 3-1. Checking the Voltage Functions (Output Terminals Open)  
Procedure  
Display  
Output Terminals Open or Connected to a Voltmeter  
If Dis is on, turn it off by pressing  
Explanation  
Press  
Press  
key  
VOLT 0.000  
Default voltage setting. CV annunciator should be on. (If CC annunicator  
is on, increase the current by pressing  
one or more times until  
CC turns off and CV turns on.)  
VOLT 4  
4.000  
Program output to 4 volts.  
Press  
Enter the voltage. Meter mode displays output voltage. During these  
tests, there may be a small (relative to full output) AMPS reading that  
will be ignored.  
Press  
times  
several  
Voltage decreases several millivolts each time you press the key.*  
Press  
the same  
Voltage increases several millivolts each time you press the key.*  
number of times  
* The number of millivolts change is determined by the voltage programming resolution of  
your power supply (see "Supplemental Characteristics" in Chapter 1).  
Rotate Voltage control first  
counterclockwise and then  
clockwise  
Control operates similarly to  
is rate sensitive. Turning it more quickly causes a more rapid change in  
voltage.  
and  
keys. The control  
Press  
Press  
4.000  
Program output to 4 volts.  
Display shows default OVP (overvoltage protection) trip voltage for your  
supply (see "Supplemental Characteristics" in Chapter 1).  
Press  
Press  
OV  
3
Program the OVP to 3 volts, which is less than the output voltage.  
0.000  
OVP voltage entered is less than the output voltage. This causes the OVP  
circuit to trip. The output drops to zero, CV turns off, and Prot turns on.  
OV - - - - -  
Shows that the power supply shuts down because the OVP circuit has  
tripped.  
Press  
Press  
Press  
Return display to meter mode (optional step).  
0.000  
4.000  
Program the OVP to 4.5 volts, which is greater than the output voltage.  
Note: You cannot clear an OVP trip until you have first removed the  
cause of the condition.  
Press Prot Clear  
The OVP circuit is cleared, restoring the output. Prot turns off and CV  
(
)*  
turns on.  
*
is the unlabeled blue key.  
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Checking the Current Function  
ENERGY HAZARD. Some supplies (Series 668xA) can provide more than 240 VA at more than  
2 V. If the output connections touch, severe arcing may occur resulting in burns, ignition or welding of  
parts. Do not attempt to make connections while the output is live.  
The tests in Table 3-2 check the basic current functions with a short connected across the power supply output. Do not  
program maximum output currents unless the shorting wire is capable of handling the current (see "Supplemental  
Characteristics" and Table 4-2). The AMPS display will show various readings. Ignore the VOLTS display.  
Table 3-2. Checking the Current Functions (Output Terminals Shorted)  
Action  
Display  
Explanation  
Turn off the power supply and connect a #14 AWG or larger wire across the output (+) and (-) terminals. If you intend to  
test at full-rated output current, use a wire or wires of sufficient size to carry the maximum current of the supply  
(see "Supplemental Characteristics" in Chapter l and Table 4-2 in Chapter 4).  
Turn on the supply.  
Meter mode  
Essentially zero outputs with Dis annunciator on.  
Set the voltage to its maximum  
value. This example assumes that  
you have an 8-volt supply (see  
"Performance Specifications" in  
Chapter 1 for the value for your  
specific supply) .  
Press  
Press  
VOLT 8.000  
AMPS 1.000  
Program output to 8 volts.  
Program output to 1 ampere.  
CAUTION: Be certain to observe this step with Series 668xA supplies. Start at  
1 ampere before going to greater output currents.  
Press  
AMPS 1. 000  
Dis annunciator turns off, CC annunciator turns on, and AMPS  
display shows the programmed current.  
Press  
several times  
the same  
*Current decreases several milliamperes each time you press the  
key.:  
*Current increases several milliamperes each time you press the  
key.  
Press  
number of times  
*The number of milliamperes is determined by the current programming resolution of  
the power supply (see "Supplemental Characteristics" in Chapter 1).  
Rotate the Current control first  
counterclockwise and then  
clockwise  
Control operates similarly to the  
The control is rate sensitive. Turning it more quickly causes a  
more rapid change in current.  
and  
keys.  
Press  
You have enabled the overcurrent protection circuit. The circuit  
then tripped because of the output short. The CC annunciator  
turns off and the OCP and Prot annunciators come on. The  
output current is near zero.  
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Table 3-2. Checking the Current Functions (Output Terminals Shorted) (continued)  
Action  
Display  
Explanation  
Press  
Press  
AMPS 0.000  
Dis annunciator turns on.  
You have disabled the overcurrent protection circuit. The OCP  
annunciator turns off.  
Press  
You have cleared the overcurrent protection circuit. The Prot  
annunciator turns off.  
(
)**  
Press  
AMPS 1.000  
Dis turns off and CC turns on. The output current is restored.  
If you have a shorting wire of sufficient capacity, you may continue testing up to the maximum rated current of the power  
supply (see "Performance Specifications"). When finished, go to the next step.  
Press  
AMPS 0.000  
Turn off the power supply and remove the short from the output terminals.  
** is the unlabeled blue key.  
Dis turns on and output current drops to zero.  
Checking The Save And Recall Functions (All Models)  
The Series 668xA supplies have four nonvolatile memory storage locations (0 through 3). The supplies of all other series  
have five (locations 0 through 4). Proceed as follows:  
■
■
Make certain that the output is on (Dis annunciator is off).  
Set the voltage output to 5 by pressing  
.
■
■
Save this value to location 1 by pressing  
.
Return the output voltage to 0 by pressing  
(This step is based on the fact that a newly shipped power  
supply has the *RST parameters stored in location 0 (see "Chapter 5 - Front Panel" for more information).  
Press and notice that the output voltage returns to the value stored in location 1.  
■
Determining The GPIB Address (All Models)  
When the power supply is turned on, the display shows ADDR n, where n is the power supply GPIB address. Any time you  
want to see the address, press  
.
The display will indicate ADDR 5, which is the factory default. If the address has been changed, then a different number  
will appear (see “Setting the GPIB Address” in “Chapter 5 - Front Panel”).  
In Case Of Trouble  
Line Fuse  
If the power supply appears "dead" with a blank display and the fan not running, first check your power source to be certain  
line voltage is being supplied to the power supply. If the power source is normal, the power supply line fuse may be  
defective. (On Series 668xA supplies, if the Check Fuses LED is blinking, then one or two of the line fuses are open.) If  
the supply has a defective fuse, replace it only once. If it fails again, investigate the reason for the failure. Proceed as  
follows:  
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Series 664xA and 665xA Supplies  
The line fuse is located on the rear panel (3, Figure 2-l). Proceed as follows:  
1. Turn off the front panel power switch.  
2. Using a screwdriver, remove the fuse from the fuseholder. Replace it with one of the same type (see Table 1-5 in  
Chapter l). Do not use a time-delay type fuse.  
3. Turn on the power supply and check the operation.  
Series 667xA Supplies  
Hazardous voltage can remain inside the power supply even after it has been turned off. Fuse  
replacement should be done only by qualified electronics personnel.  
The line fuse is located inside the power supply. To change it, proceed as follows:  
l. Turn off the front panel power switch and unplug the line cord from the power source.  
2. Remove the power supply dustcover as follows:  
a. Remove the four screws securing the carrying straps and dustcover.  
b. Spread the bottom rear of the dustcover and pull it back to disengage it from the front panel.  
c. Slide the dustcover back far enough to expose the line fuse (l, Figure 3-l).  
3. Observe the input rail LED under the RFI shield (4, Figure C-3 in "Appendix C - Line Voltage Conversion"). If the  
LED is on, there is still hazardous voltage inside the supply. Wait until the LED goes out (this may take several  
minutes) before proceeding.  
4. Connect a dc voltmeter across test points TPl and TP2 (Figure C-3). It may be necessary to remove the RFI shield in  
order to reach these test points. (The shield is secured by four screws on each side.) When the voltmeter indicates 60 volts  
or less, it is safe to work inside the power supply.  
5. Replace the fuse with one of the same type (see Table 1-5 in Chapter l). Do not use a time-delay type fuse.  
6. If you removed it in step b, be sure to replace the RFI shield.  
7. Replace the dustcover.  
8. Connect the line cord to the power source.  
9. Turn on the front panel power switch and check the operation.  
€ Power Fuse ó Line Filter ì Rear of Power Supply  
Figure 3-1. Series 667xA Line Fuse  
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Series 668xA Supplies  
The line fuses are located on the rear panel (see Figure 2-4). Proceed as follows:  
l. Turn off the front panel power switch and remove the input power (unplug the power cord or open the safety  
disconnect).  
2. Remove the ac input safety cover from the rear panel.  
3. Unscrew the fuse caps and remove the fuses.  
4. If one or two fuses are defective, replace all three with fuses of the same type (see Table 1-5 in Chapter l).  
Note:  
If all three fuses are blown, the Check Fuses LED will not blink and the power supply probably has a  
defect that requires service.  
5. Turn on the power supply and check the operation. If it is normal, replace the ac input safety cover.  
Maintenance Note It is recommended that new line fuses be installed every four years.  
Condensation Fault (Series 668xA Only)  
If the front panel Dew LED is on, then there is excessive (near 100%) humidity inside the power supply. (This could occur  
if the supply is rapidly moved from a cold to a warm environment.) The power supply will not turn on when this LED is lit.  
If the LED remains on under conditions of normal humidity, the power supply has a defect and requires service. If  
condensation occurs after the supply is successfully turned-on, the Dew detector circuit will not turn off the supply.  
Error Messages (All Models)  
Power supply failure may occur during power-on selftest or during operation. In either case, the display may show an error  
message that indicates the reason for the failure.  
Selftest Errors  
When a selftest error occurs, it prevents all front panel operation. The display may show either a power-on error message or  
a checksum error message.  
Power-On Error Messages  
Power-on messages appear as:  
En- - - - - -  
Where "n" is a number listed in Table 3-3. If this occurs, turn the power off and then back on to see if the error persists. It is  
possible to recover from the EE CHKSUM error (see "Checksum Errors"). If any other message persists, the power supply  
requires service.  
Table 3-3. Power-On Selftest Errors  
Error  
No.  
Display  
Failed Test  
Error  
No.  
Display  
Failed Test  
Secondary RAM  
Secondary ROM checksum  
Secondary 5 V ADC  
reading  
El FP RAM  
E2 FP ROM  
E3 EE  
Front Panel RAM  
Front Panel ROM checksum  
EEPROM  
E8 SEC RAM  
E9 SEC ROM  
E10 SEC 5V  
CHKSUM  
E4 PRI XRAM  
E5 PRI IRAM  
E6 PRI ROM  
E7 GPIB  
Primary external RAM  
Primary internal RAM  
Primary ROM checksum  
GPIB R/W to serial poll  
Ell TEMP  
E12 DACS  
Secondary ambient  
thermistor reading  
Secondary VDAC/IDAC  
readback  
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Checksum Errors.  
If the display shows EE CHKSUM, the power supply has detected an EEPROM checksum error. A checksum error can  
occur due to the following conditions:  
■
Excessive number of write cycles to an EEPROM (see "Nonvolatile Memory Write Cycles" in "Supplemental  
Characteristics" tables). This condition, which would appear only after extended use, is not recoverable and requires  
service.  
■
Loss of ac input power during a checksum calculation. This condition, which is very unlikely, is recoverable.  
You may be able to recover from a checksum error by writing to the EEPROM while the power supply is in the calibration  
mode. To do this, proceed as follows:  
1. Enable the calibration mode by pressing  
.
2. PASWD will appear on the display.  
3. Press the number keys corresponding to the password, followed by  
. The Cal annunciator will go on.  
Note  
On new equipment, the calibration password corresponds to the four-digit model number (such as  
). See "Appendix A - Calibration" for more information about the calibration password.  
4. Save any operating state (for example, press  
5. Turn the power off and then back on.  
).  
A normal display free of error messages should appear. If not, the power supply requires service.  
Runtime Error Messages  
Under unusual operating conditions, the VOLT or AMPS display may show +OL or -OL. This indicates that the output  
voltage or current is beyond the range of the meter readback circuit. Table 3-4 shows other error messages that may appear  
at runtime.  
Table 3-4. Runtime Errors  
Display  
EE WRITE ERR  
SBUB FULL  
Meaning  
EEPROM status timeout  
Message too long for buffer  
Display  
Meaning  
UART FRAMING UART byte framing error  
UART  
OVERRUN  
UART PARITY  
Overfilled UART receive buffer  
UART byte parity error panel  
SERIAL DOWN  
Failed communication with  
front  
STK OVERFLOW Front panel stack overflow  
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4
User Connections  
Rear Panel Connections (All Models)  
Make application load connections to the output terminals or bus bars, analog connector, and digital connector as shown on  
the rear-panel drawing for your model power supply. These connections are organized by series as follows:  
l Series 664xA and 665xA  
l Series 667xA  
l Series 668xA  
Make controller connections (GPIB and serial link) as shown in Figure 4-6 at the end of this chapter.  
Load Wire Selection (All Models)  
Fire Hazard To satisfy safety requirements, load wires must be large enough not to overheat when  
carrying the maximum short-circuit current of the power supply. If there is more than one load, then  
any pair of load wires must be capable of safely carrying the full-rated current of the supply. With  
the larger-capacity supplies (such as Series 668xA), use of two or more load wires in parallel may be  
required.  
Table 4-1 lists the characteristics of AWG (American Wire Gauge) copper wire.  
Table 4-1. Stranded Copper Wire Capacity and Resistance  
AWG  
No.  
14  
12  
10  
8
Ampacityl  
Resistance2  
(Ω/m)  
AWG  
No.  
2
1/0  
2/0  
3/0  
4/0  
Ampacity1  
Resistance2  
(Ω/m)  
25  
30  
40  
60  
80  
0.0103  
140  
195  
225  
260  
300  
0.00064  
0.00040  
0.00032  
0.00025  
0.00020  
0.0065  
0.0041  
0.0025  
0.0016  
6
4
105  
0.0010  
NOTES:  
1. Ampacity is based on 30 °C ambient temperature with conductor rated at 60 °C. For ambient temperature other  
than 30 °C, multiply the above ampacities by the following constants:  
Temp (°C) Constant  
Temp (°C) Constant  
41-45 0.71  
21-25 1.08  
26-30 1.00  
46-50 0.58  
31-35 0.91  
51-55 0.41  
36-40 0.82  
2. Resistance is nominal at 75 °C wire temperature.  
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Analog Connector (All Models)  
This connector, which is on the rear panel, is for connecting remote sense leads, external current monitors, and external  
programming sources. The connector accepts wires sizes from AWG 22 to AWG 12.  
€ Insert Wires  
Agilent Series 664xA & 665xA  
ó Tighten Screws  
Agilent Series 667xA & 668xA  
IP Current programming input.  
VP Voltage programming input.  
+IM Current monitor output.  
--IM Current monitor output.  
↓P Common for VP, IP and IM signals1.  
+ S + remote sense input.  
IM Current monitor output.  
VP Voltage programming input.  
+IP Differential current programming input.  
--IP Differential current programming input.  
↓P Common for VP and IM signals1.  
+S + remote sense input.  
--S -remote sense input.  
--S -remote sense input.  
NOTE 1: Referenced to + output terminal.  
Figure 4-1. Rear Panel Analog Connector  
Note  
It is good engineering practice to twist and shield all signal wires to and from the analog and digital  
connectors.  
Digital Connector (All Models)  
This connector, which is on the rear panel, is for connecting fault/inhibit, digital I/O, or relay link signals. The connector  
accepts wires sizes from AWG 22 to AWG 12.  
€ Insert Wires  
ó Tighten Screws  
FUNCTION1  
Pin  
No.  
1
2
3
Fault/Inhibit  
Digital I/O  
Relay Link2  
FLT OUTPUT  
FLT OUTPUT  
INH INPUT  
OUT 0  
OUT 1  
IN/OUT 2  
COMMON  
RLY SEND  
NOT USED  
RLY RTN  
COMMON  
4
INH COMMON  
NOTES: Factory default function is FAULT/INHIBIT.  
Output relay is not used with Series 668xA.  
Figure 4-2. Rear Panel Digital Connector  
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Connecting Series 664xA and 665xA Power Supplies To The Load  
€ Output Safety Cover  
öSignal Common  
ó + Output Terminal  
ú Output Sense Switch  
ì - Output Terminal  
÷ Analog Connector  
Figure 4-3a. Series 664xA and 665xA Rear Panel Output Connections  
Output Isolation  
The output of the power supply is isolated from earth ground. Either output terminal may be grounded, or an external  
voltage source may be connected between either output and ground. However, both output terminals must be kept within  
± 240 Vdc of ground. An earth ground terminal is provided on the rear panel for convenience, such as grounding wire  
shields.  
The earth ground terminal on the rear panel is a low-noise signal ground for convenience only. It is  
not designed to function as a safety ground.  
Load Considerations  
Capacitive Loads  
Effect on the Output Circuit. In most cases, the power supply will continue to be stable with additional external load  
capacitors (see the following table for recommendations). However, large load capacitors may cause ringing in the supply’s  
transient response. It is possible that certain combinations of load capacitance, equivalent series resistance, and load lead  
inductance will result in instability. If you need help in solving a stability problem, contact an Agilent service engineer  
through your local Sales and Support Office (see end of this guide).  
Series 664xA/665xA Power Supplies, Maximum External Capacitance (µF)  
6641A  
6642A  
6643A  
6644A  
6645A  
6651A  
6652A  
6653A  
6654A  
6655A  
40,000  
20,000  
12,000  
7,000  
3,000  
100,000  
50,000  
30,000  
18,000  
8,000  
If the power supply output is rapidly programmed into capacitive loads, the supply may momentarily cross into CC mode.  
This extends the CV programming time and limits the maximum slew rate to the programmed current divided by the total  
internal (see the following section “Inductive Loads”) and external capacitance. These momentary crossovers into CC mode  
will not damage the supply.  
Effect on the OVP Circuit. The OVP circuit is designed to discharge fully-charged capacitances up to a specified limit for  
each model. These limits are as follows:  
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Series 664xA/665xA Power Supplies, Maximum OVP External Capacitance (µF)  
6641A  
6642A  
6643A  
6644A  
6645A  
6651A  
6652A  
6653A  
6654A  
6655A  
700,000  
35,000  
15,000  
7,000  
3,000  
1.6 (F)  
100,000  
50,000  
18,000  
8,000  
If a load capacitance approaches the specified limit, it is recommended that you do not make it a normal practice of tripping  
the OVP circuit and discharging the load capacitance through that circuit. This could cause long-term fatigue in some circuit  
components.  
Because of its high output voltage, the Agilent 6555A generates very high currents when discharging  
the load capacitor under overvoltage conditions. Excessive currents can damage the supply. The peak  
discharge current is limited by the sum of the external capacitor’s ESR (equivalent series resistance)  
and the series resistance of the external circuit. For the Agilent 6555A external capacitance limit of  
8,000 µF, this total resistance must be not less than 56 milliohms. For smaller values of external  
capacitance, this resistance may be derated linearly.  
Inductive Loads  
Inductive loads provide no loop stability problems in CV mode. However, in CC mode inductive loads will form a parallel  
resonance network with the power supply’s output capacitor. Generally, this will not affect the stability of the supply, but it  
may cause ringing of the current in the load. Ringing will not occur if the Q (quality factor) of the parallel resonant network  
is ≤ 0.5. Use the following formula to determine the Q of your output.  
1
L
C
Q =  
Rint + Rext  
where: C = model-dependent internal capacitance (see below); L = inductance of the load; Rext = equivalent series  
resistance of the load; Rint = model-dependent internal resistance (see below):  
6641A  
4,200 µF  
7 mΩ  
6642A  
550 µF 180 µF 68 µF  
30 mΩ 50 mΩ  
6643A  
6644A  
6645A  
33 µF  
6651A  
10,000 µF  
6652A  
1100 µF 440 µF  
20 mΩ 30 mΩ  
6653A  
6654A  
120 µF  
80 mΩ  
6655A  
50 µF  
250 mΩ  
C =  
R int  
=
125 mΩ 300 mΩ 4 mΩ  
Battery Charging  
The power supply’s OVP circuit contains a crowbar SCR that effectively shorts the output of the supply whenever OVP  
trips. If a battery (or other external voltage source) is connected across the output and the OVP is inadvertently triggered or  
the output is programmed below the battery voltage, the power supply will continuously sink a large current from the  
battery. This could damage the supply. To avoid this, insert a reverse blocking diode in series with the ⊕ output of the  
supply. Connect the diode cathode to the + battery terminal and the diode anode to the supply ⊕ output terminal. The  
diode may require a heat sink.  
Note that if the OVP trips, you must remove the external current source in order to reset the internal SCR as part of clearing  
the OVP circuit (see Clearing the OV Condition in “Chapter 5 - Front Panel Operation”).  
Local Voltage Sensing  
Your power supply was shipped set up for local sensing. This means that the supply will sense and regulate its output at the  
output terminals, not at the load. Since local sensing does not compensate for voltage drops across screw terminals, bus  
bars, or load leads, local sensing should only be used in applications that require low output current or where load regulation  
is not critical.  
Local sensing is obtained by placing the SENSE switch (see Figure 4-3a) in the Local position. The power supply is  
shipped with the switch in this position.  
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Note  
If the sense terminals are left unconnected, the voltage at the bus bars will increase approximately 3 to 5%  
over the programmed value. Since it is measured at the sense terminals, the voltage readback will not  
reflect this increased output.  
Remote Voltage Sensing  
The dashed lines in the wiring diagrams illustrate remote voltage sensing. The remote sense terminals of the power supply  
are connected directly to the load rather than to the output terminals. This allows the supply to automatically compensate for  
the voltage drop in the load leads as well as to accurately read back the voltage directly across the load.  
Setting Up Remote Sense Operation  
Remote sensing is obtained by placing the SENSE switch (see Figure 4-3a) in the Remote position. The power supply is  
shipped with the switch in the Local position.  
Connecting The Sense Leads  
You must connect the positive side of the load to the +S analog connector pin and the negative side of the load to the  
-S analog connector pin (see Figure 4-1). Connect the sense leads carefully so that they do not become open-circuited. If  
sense leads are left open during operation, the supply will regulate at the output terminals instead of at the load. Remember  
to bundle or tie wrap the load leads to minimize inductance and reduce noise pickup.  
CV Regulation  
The voltage load regulation specification in Table 1-la and Table 1-2a applies at the output terminals of the power supply.  
When remote sensing, this specification must be compensated. Add 3 mV to the voltage load regulation specification for  
each 1-volt change in the positive load lead due to a change in load current. Because the sense leads are part of the supply’s  
feedback path, keep the resistance of the sense leads at or below 0.5 Ω to maintain the above specified performance.  
OVP Considerations  
The OVP circuit senses the voltage near the output terminals, not at the sense terminals. The voltage sensed by the OVP  
circuit can be significantly higher than the voltage being maintained at the load. When using remote sensing, you must  
program the OVP high enough to compensate for the expected voltage drop between the output and the load.  
Output Rating  
The rated output voltage and current specification in Table l-la and Table 1-2a applies at the output terminals of the power  
supply. With remote sensing, any voltage dropped in the load leads causes the supply to increase the voltage at the output  
terminals so it can maintain the proper voltage at the load. When you attempt to operate at the full-rated output at the load,  
this forces the supply voltage at the output terminals to exceed the supply’s rated output.  
This will not damage the supply, but may trip the OVP (overvoltage protection) circuit, which senses the voltage at the  
output. When operated beyond its rated output, the supply’s performance specifications are not guaranteed, although typical  
performance may be good. If the excessive demand on the supply forces it to lose regulation, the Unr annunciator will  
indicate that the output is unregulated.  
Output Noise  
Any noise picked up on the sense leads also appears at the output of the power supply and may adversely affect the load  
voltage regulation. Be sure to twist the sense leads to minimize external noise pickup and route them parallel and close to  
the load leads. In noisy environments, it may be necessary to shield the sense leads. Ground the shield only at the power  
supply. Do not use the shield as one of the sense conductors.  
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Stability  
Using remote sensing under unusual combinations of load-lead lengths and large load capacitances may cause your  
application to form a low-pass filter that becomes part of the voltage feedback loop. The extra phase shift created by this  
filter can degrade the supply’s stability and result in poor transient response. In severe cases, this may cause output  
oscillations. To minimize this possibility, keep the load leads as short as possible and tie wrap them together.  
In most cases, following the above guidelines will prevent problems associated with load lead inductance. This leaves load  
load-lead resistance and load capacitance as the major source of reduced stability. Further improvement to the stability of  
the supply may be obtained by keeping the load capacitance as small as possible and by decreasing the load-lead resistance  
by using larger diameter wires. However, if heavy gauge wire (≥ AWG 10) is used, conditions may arise where the  
load-lead inductance and load capacitance can form an undamped filter. This can actually reduce the damping in the system  
and create a destabilizing phase response.  
Note  
If you need help in solving a stability problem with any Series 664xA or 665xA power supply contact an  
Agilent Service Engineer through your local Agilent Sales and Support Offices.  
Operating Configurations  
Figure 4-3b through Figure 4-3f show the various configurations for connecting to the load. Figure 4-3g shows how to  
connect an external voltage source for analog programming.  
Connecting One Supply to the Load  
Figure 4-3b and Figure 4-3c show how to connect a single power supply to one load and to multiple loads.  
€ Load Connection  
ó Load  
ì Analog Connector  
A Set switch for local or optional remote sensing  
B Connect for remote sensing (optional)  
Figure 4-3b. Series 664xA and 665xA Single Load Connection  
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€ Load Connection  
ó Loads  
ì Analog Connector  
A Set switch for local or (optional) remote sensing  
B Connect for remote sensing (optional)  
Figure 4-3c. Series 664xA and 665xA Multiple Load Connection (Remote Sensing Optional)  
Connecting Supplies in Auto-Parallel  
Auto-Parallel Wiring. Figure 4-3d illustrates how power supplies can be connected in auto-parallel for increased current  
output. You can connect up to three supplies of the same model .  
Use load leads of a sufficient wire size so that the absolute voltage difference between the + output terminal of the "master"  
supply and the + output terminal of the first "slave" supply is kept under 2 V at rated current. This also applies to the  
voltage difference between the + output terminals of the first and second slave supplies. If remote sensing is required,  
connect the load to the remote sense terminals of the master supply, as shown by the dashed lines in Figure 4-3d.  
€Analog Connector  
óSlave Supply  
ì Master Supply  
öProgram only the master. Set slave output and OVP voltages slightly higher than the master to ensure that slaves stay in  
CC mode.  
úLoad  
÷Connection  
A Only local sensing permitted  
B Set switch for optional remote sensing  
C Connect for remote sensing (optional)  
Figure 4-3d. Series 664xA and 665xA Auto-Parallel Connection (Remote Sensing Optional)  
Note  
To avoid output oscillations, observe the wiring suggestions given under “External Voltage Control”.  
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Auto-Parallel Programming. Program only the first ("master") supply in the series; the "slave" supplies automatically  
track the master’s output. However, the voltage and OVP settings of the slave supplies must be set higher than the operating  
voltage of the master supply. This ensures that the slave supplies will operate in CC mode. Functions such as status, voltage  
readback, and current readback can still be read back individually for each supply.  
If a "slave" supply experiences a desired shutdown condition (such as overtemperature or overcurrent), it will not  
automatically shut down all other supplies. You must first enable remote inhibit (RI) and discrete fault indicator (DFI)  
operation. See "Fault/Inhibit Operation" in Appendix D for wiring information and "Questionable Status Group" in  
Chapter 4 of the Programming Guide for programming information.  
Follow the following operating precautions if you are connecting three of these models in auto-parallel.  
You must use caution when connecting three Series 664xA or 665xA power supplies for auto-parallel operation. That is  
because of the OVP crowbar circuits within these supplies. If the OVP circuit of the second "slave" trips, its crowbar circuit  
will draw current from the other two supplies. Although some models can withstand this current, the higher-current models  
in each series (particularly the Agilent 6651A) may be damaged in this situation. Use any of the following operating  
techniques to avoid possible problems.  
1. Program Slave 2 OVP to the Maximum Level  
The following technique minimizes the chance that the slave 2 OVP circuit will trip.  
a. Program the OVP level of the master and of slave 1 to the desired protection level (below the maximum level  
specified in Table 1-2).  
b. Program the OV protection level of slave 2 to its maximum value.  
2. Enable OCP on the Master  
You can do this if the combination of all three supplies is being used in the CV mode and the CC mode is only being used as  
a current limit. Enable OCP on the master supply. If the OVP on either slave trips it will drive the master into CC mode,  
thereby tripping its OCP. This will shut down all three supplies. This technique will work unless the system is programmed  
for very low (0.5 to 1.5) output voltages.  
3. Insert Protection Diodes  
If you connect the slave 2 supply to the load through a series diode (see Figure 4-3e), its OVP circuit will not draw current  
from other supplies. Be certain to increase the programmed CV level of slave 2 by at least 0.7 V to compensate for the  
voltage drop in the diode.  
Figure 4-3e. Using Series Diodes with Series 664xA & 665xA Auto-Parallel Operation  
Note  
Removing or disabling the power supply OVP crowbar SCR is another possibility. For further  
information, contact a Agilent Service Engineer through your local Agilent Sales and Support Offices.  
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Connecting Supplies in Series  
Floating voltages must not exceed ±240 Vdc. No output terminal may be more than 240 V from  
chassis ground.  
Figure 4-3f shows how power supplies can be connected in series for higher voltage output.  
Series connections are straightforward in this case. Program each power supply independently. If two supplies are used in  
the series configuration, program each supply for 50% of the total output voltage. Set the current limit of each supply to the  
maximum that the load can handle without damage.  
Each power supply has a reverse voltage protection diode across its output. If a reverse voltage is  
applied, the supply cannot control the current conducted through this diode. To avoid damaging the  
supply, never connect it in such a way that a reverse voltage can force it to conduct current in  
excess of the supply’s maximum reverse diode current (see Table 1-2).  
€Analog Connector  
óLoad Connection  
ìLoad  
A Program each supply for full load current and 1/2 the load voltage  
B Set switch for local or (optional) remote sensing  
C Connect for remote sensing (optional)  
WARNING  
FLOATING VOLTAGES MUST NOT EXCEED ±240 VDC. NO OUTPUT TERMINAL MAY  
BE MORE THAN 240 V FROM CHASSIS GROUND  
Figure 4-3f. Series 664xA and 665xA Series Connection (Remote Sensing Optional)  
External Voltage Control  
The setup shown in Figure 4-3g allows an external dc voltage to program the power supply output. A voltage applied to the  
voltage programming input programs the output voltage and a voltage applied to the current programming input programs  
the output current. See Figure 4-1 for an explanation of these programming input connections.  
Wiring Considerations  
The input impedance of the analog input is 10 kΩ. If the output impedance of your programming source is not negligible  
with this, programming errors will result. Larger output impedances result in proportionally greater errors.  
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Be careful of capacitive coupling from the programming inputs to other lines wired to the analog connector. Such coupling  
can cause output oscillations. You can minimize coupling by bundling the IP, VP, and Common P lines and keeping them  
separated from other wires. Twisting these three lines together is also recommended.  
€ Analog connector  
l=Voltage programming source 0 to--5 V  
2=Current programming source 0 to +10 V  
Figure 4-3g. Series 664xA and 665xA Analog Programming Connections  
If you cannot avoid capacitive coupling, it may help to place capacitors from the unused programming inputs to ground.  
Especially with auto-parallel operation, connecting a capacitor (≥4,000 pF) from VP to P Common on the master supply  
will ensure proper operation. Also with auto-parallel operation, do not allow more than about 500 pF capacitive loading  
between IM and Common P.  
Programming Considerations. When voltage programming the output, the frequency of the programming source is limited  
by the slew rate of the power supply. To keep the power supply from slewing its output (going into nonlinear operation), the  
maximum programming rate is 3750 V/s. The maximum downprogramming rate (when the power supply is sinking current)  
is 750 V/s. These restrictions can be expressed as the maximum programming frequency that can be applied without causing  
distortion at the output. The following formula can be used to determine this frequency:  
F MAX  
=
50(voltage rating of supply)  
p-p amplitude of desired output sine wave  
At frequencies >6 kHz, voltage programming is subject to a 3 dB bandwidth limitation.  
Connecting Series 667xA Power Supplies To The Load  
Output Isolation  
The output of the power supply is isolated from earth ground. Either output terminal may be grounded, or an external  
voltage source may be connected between either output and ground. However, both output terminals must be kept within  
± 240 Vdc of ground. An earth ground terminal is provided on the rear panel for convenience, such as grounding wire  
shields.  
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€ Output Safety Cover  
ö-Local Sense Terminal  
ø Signal Common  
ó Analog Connector  
ú + Local Sense Terminal  
í Local Sense Jumpers  
ì-Output Bus Bar  
÷+ Output Bus Bar  
û Rear Knockouts  
ç Bottom Knockout  
A Insert screwdriver blade in slot and pry out  
B Bend along joint and break off  
WARNING  
DO NOT LEAVE UNCOVERED HOLES IN OUTPUT COVER. IF TOO MANY  
KNOCKOUTS HAVE BEEN REMOVED, INSTALL A NEW COVER.  
Figure 4-4a. Series 667xA Rear Panel Output Connections  
The earth ground terminal on the rear panel is a low-noise signal ground for convenience only. It is not  
designed to function as a safety ground.  
Load Considerations  
Capacitive Loads  
In most cases, the power supply will continue to be stable with additional external load capacitors. However, large load  
capacitors may cause ringing in the supply’s transient response. It is possible that certain combinations of load capacitance,  
equivalent series resistance, and load lead inductance will result in instability. If you need help in solving a stability  
problem, contact a service engineer through your local Sales and Support Offices (see end of this guide).  
If the power supply output is rapidly programmed into capacitive loads, the supply may momentarily cross into constant  
current (CC) mode. This extends the CV programming time and limits the maximum slew rate to the programmed current  
divided by the total internal and external capacitance. These momentary crossovers into CC mode will not damage the  
supply.  
Inductive Loads  
Inductive loads provide no loop stability problems in CV mode. However, in CC mode inductive loads will form a parallel  
resonance network with the power supply’s output capacitor. Generally, this will not affect the stability of the supply, but it  
may cause ringing of the current in the load. Ringing will not occur if the Q (quality factor) of the parallel resonant network  
is ≤1.0. Use the following formula to determine the Q of your output.  
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1
L
C
Q =  
R int+ Re xt  
where: C = model-dependent internal capacitance (see below); L = inductance of the load; Rext = equivalent series  
resistance of the load; Rint = model-dependent internal resistance (see below):  
6671A  
44,000 µF  
1.8 mΩ  
6672A  
44,000 µF  
2.2 mΩ  
6673A  
12,000µF  
4 mΩ  
6674A  
7,000 µF  
14 mΩ  
6675A  
2,100 µF  
30 mΩ  
C=  
R int=  
If the Q is greater than 0.5, inductive loads will ring with the output capacitance and will be damped according to the  
following equation:  
δ =  
Battery Charging  
The power supply’s OVP circuit has a downprogrammer FET that discharges the power supply output whenever OVP trips.  
If a battery (or other external voltage source) is connected across the output and the OVP is inadvertently triggered or the  
output is programmed below the battery voltage, the power supply will sink current from the battery. To avoid this, insert a  
reverse blocking diode in series with the ⊕ output of the supply. Connect the diode cathode to the + battery terminal and the  
diode anode to the supply ⊕ output terminal. The diode may require a heat sink.  
Local Voltage Sensing  
Your power supply was shipped set up for local sensing. This means that the supply will sense and regulate its output at the  
output terminals, not at the load. Since local sensing does not compensate for voltage drops across screw terminals, bus  
bars, or load leads, local sensing should only be used in applications that require low output current or where load regulation  
is not critical.  
Local sensing is obtained by connecting the +LS sense terminal to the +S analog connector pin and the pin and the -LS  
sense terminal to the -S analog connector pin. The power supply is shipped with these connections made.  
Note  
If the sense terminals are left unconnected, the voltage at the bus bars will increase approximately 3 to 5%  
over the programmed value. Since it is measured at the sense terminals, the voltage readback will not  
reflect this increased output.  
Remote Voltage Sensing  
The dashed lines in the wiring diagrams illustrate remote voltage sensing. The remote sense terminals of the power supply  
are connected directly to the load rather than to the output terminals. This allows the supply to automatically compensate for  
the voltage drop in the load leads as well as to accurately read back the voltage directly across the load.  
Setting Up Remote Sense Operation  
Remote sensing is obtained by removing the jumpers connecting the +LS sense terminal to the +S analog connector pin and  
the -LS sense terminal to the -S analog connector pin. The power supply is shipped with these jumpers connected.  
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Connecting the Sense Leads  
You must connect the positive side of the load to the +S analog connector pin and the negative side of the load to the -S  
analog connector pin (see Figure 4-1). Connect the sense leads carefully so that they do not become open-circuited. If sense  
leads are left open during operation, the supply will regulate at the output terminals instead of at the load. Remember to  
bundle or tie wrap the load leads to minimize inductance and reduce noise pickup.  
CV Regulation  
The voltage load regulation specification in Table 1-3a applies at the output terminals of the power supply. When remote  
sensing, this specification must be compensated. Add an increment to the voltage load regulation specification as specified  
by “∆mV” in the equation given under Load regulation in Table 1-3b.  
Output Rating  
The rated output voltage and current specification in Table 1-3a applies at the output terminals of the power supply. With  
remote sensing, any voltage dropped in the load leads causes the supply to increase the voltage at the output terminals so it  
can maintain the proper voltage at the load. When you attempt to operate at the full-rated output at the load, this forces the  
supply voltage at the output terminals to exceed the supply's rated output. This will not damage the supply, but may trip the  
OVP (overvoltage protection) circuit, which senses the voltage at the output bus bars. When operated beyond its rated  
output, the supply's performance specifications are not guaranteed, although typical performance may be good. If the  
excessive demand on the supply forces it to lose regulation, the Unr annunciator will indicate that the output is unregulated.  
Output Noise  
Any noise picked up on the sense leads also appears at the output of the power supply and may adversely affect the load  
voltage regulation. Be sure to twist the sense leads to minimize external noise pickup and route them parallel and close to  
the load leads. In noisy environments, it may be necessary to shield the sense leads. Ground the shield only at the power  
supply. Do not use the shield as one of the sense conductors.  
Note  
The signal ground binding post on the rear panel is a convenient place to ground the sense shield.  
OVP Considerations  
The OVP circuit senses the voltage near the output terminals and not at the sense terminals. Depending on the voltage drop  
between the output terminals and the load, the voltage sensed by the OVP circuit can be significantly higher than actually  
being regulated at the load. You must program the OVP trip high enough to compensate for the expected higher voltage at  
the output terminals.  
Stability  
Using remote sensing under unusual combinations of load-lead lengths and large load capacitances may cause your  
application to form a low-pass filter that becomes part of the voltage feedback loop. The extra phase shift created by this  
filter can degrade the supply's stability and result in poor transient response. In severe cases, this may cause output  
oscillations. To minimize this possibility, keep the load leads as short as possible and tie wrap them together.  
In most cases, following the above guidelines will prevent problems associated with load lead inductance. However, if a  
large bypass capacitor is required at the load and load-lead length cannot be reduced, then a sense-lead bypass network may  
be needed to ensure stability (see Figure 4-4b). The voltage rating of the 33 µF capacitors should be about 50% greater than  
the anticipated load-lead drop. Addition of the 20-Ω resistors will cause a slight voltage rise at the remote sensing points.  
For utmost voltage programming accuracy, the supply should be recalibrated with the DVM at the remote sensing points  
(see “Appendix A - Calibration”).  
Note  
If you need help in solving a stability problem with any Series 667xA power supply contact an Agilent  
Service Engineer through your local Agilent Sales and Support Offices.  
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€ Load Leads  
Cl, C2 = 33 µF  
óRemote Sense Points  
R1, R2 = 20 Ω, 1%  
C3 = Load bypass capacitor  
Figure 4-4b. Series 667xA Sense Lead Bypass Network  
Operating Configuration  
Figure 4-4c through Figure 4-4f show the various configurations for connecting to the load. Figure 4-4g shows how to  
connect an external voltage source for analog programming.  
Connecting One Power Supply to a Single Load (Figure 4-4c)  
Figure 4-4c shows how to connect a single power supply to one load. Keep output load leads close together (small loop  
area) to obtain a low inductance and low impedance connection to the load. If you wish to use remote sensing, connect the  
sense leads at the load as shown in the figures.  
€Load Connection  
óLoad  
ìAnalog Connector  
A Connect for remote sensing (optional)  
B Connect for local sensing (default)  
Figure 4-4c. Series 667xA Single Load Connection (Remote Sensing Optional)  
Connecting One Power Supply To Multiple Loads (Figure 4-4d)  
Figure 4-4d shows how to connect a single power supply to more than one load. When connecting multiple loads to the  
power supply with local sensing, connect each load to the output bus bars with separate connecting wires. This minimizes  
mutual coupling effects and takes full advantage of the supply’s low output impedance. Keep each pair of load wires as short  
as possible and twist or bundle them to reduce lead inductance and noise pickup.  
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€Loads  
óLoad Connection  
ìAnalog Connector  
A Connect for remote sensing (optional)  
Connect for local sensing (default)  
B
Figure 4-4d. Series 667xA Multiple Load Connection (Remote Sensing Optional)  
Connecting Supplies in Auto-Parallel  
Auto-Parallel Wiring (Figure 4-4e). Figure 4-4e illustrates how power supplies can be connected in auto-parallel for  
increased current output. You can connect up to five supplies of the same model.  
Use load leads of a sufficient wire size so that the absolute voltage difference between the + output terminal of the "master"  
supply and the + output terminal of the first "slave" supply is kept under 2 V at rated current. This also applies to the  
voltage difference between the + output terminals of the first and second slave supplies. If remote sensing is required,  
connect the load to the remote sense terminals of the master supply, as shown by the dashed lines in Figure 4-4e.  
€ Analog Connector  
ó Slave Supply  
ì Master Supply  
öProgram only the master. Set slave output and OVP voltage slightly higher than the master to ensure that slave stays in  
CC mode  
ú Load  
A Only local sensing permitted  
÷ Load Connection  
Connect for optional remote sensing  
B
Figure 4-4e. Series 667xA Auto-Parallel Connection (Remote Sensing Optional)  
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Auto-Parallel Programming. Program only the first ("master") supply in the series; the "slave" supplies automatically  
track the master’s output. However, the voltage and OVP settings of the slave supplies must be set higher than the operating  
voltage of the master supply. This ensures that the slave supplies will operate in CC mode. Functions such as status, voltage  
readback, and current readback can still be read back individually for each supply.  
If a "slave" supply experiences a desired shutdown condition (such as overtemperature or overcurrent), it will not  
automatically shut down all other supplies. You must first enable remote inhibit (RI) and discrete fault indicator (DFI)  
operation. See "Fault/Inhibit Operation" in "Appendix D - Digital Port Functions" for wiring information and "Questionable  
Status Group" in Chapter 4 of the "Programming Guide" for programming information.  
Connecting Supplies in Series  
Floating voltages must not exceed 240 Vdc. No output terminal may be more than 240 V from chassis  
ground.  
Figure 4-4f shows how power supplies can be connected in series for higher voltage output. Series connections are  
straightforward in this case.  
Program each power supply independently. If two supplies are used in the series configuration, program each supply for  
50% of the total output voltage. Set the current limit of each supply to the maximum that the load can handle without  
damage.  
Each power supply has a reverse voltage protection diode across its output. If a reverse voltage is  
applied, the supply cannot control the current conducted through this diode. To avoid damaging the  
supply, never connect it in such a way that a reverse voltage can force it to conduct current in excess  
of the supply’s maximum reverse diode current (see Table 1-2b).  
€Load Connection  
ó Analog Connector  
ì Load  
ö Program each supply for full load current and 1/2 the load voltage  
A Connect for remote sensing (optional)  
WARNING  
FLOATING VOLTAGES MUST NOT EXCEED ±240 VDC NO OUTPUT TERMINAL MAY  
BE MORE THAN 240 V FROM CHASSIS GROUND.  
Figure 4-4f. Series 667xA Series Connection (Remote Sensing Optional)  
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External Voltage Control  
The setup shown in Figure 4-4g allows an external dc voltage to program the power supply output. A voltage applied to the  
voltage programming input programs the output voltage and a voltage applied to the current programming input programs  
the output current. See Figure 4-1 for an explanation of these programming input connections.  
Wiring Considerations (Figure 4-4g)  
The input impedance of the analog input is over 30 kΩ. If the output impedance of your programming source is not  
negligible with this, programming errors will result. Larger output impedances result in proportionally greater errors.  
1 Voltage programming source 0 to -5V  
2 Differential current programming source 0 to +10 V  
3 Differential current programming source 0 to -10 V  
4 Current programming source (floating) 0 to 10 V  
* Maximum Potential between -IP and ↓P is ±15 V  
Figure 4-4g. Series 667xA Analog Programming Connections  
Programming  
Note from Figure 4-1 that you have three options for programming the current. You can use a voltage source that is positive,  
negative, or floating with respect to Common P. Do not exceed ±19 V with respect to Common P.  
Make certain that the common connection for your voltage programming source is isolated from the  
load. Failure to do this may cause damage to the power supply.  
The effect of the analog programming source is always summed with the values programmed over the GPIB or from the  
front panel. The voltage source can act alone only if you set the other program sources to zero. Keep the total programmed  
setting of the supply (the analog input summed with the GPIB or front panel settings) at or under the output ratings specified  
in Table 1-2a. Exceeding the output ratings will not damage the supply, but it may not be able to regulate its output at the  
higher levels. If this happens, the Unr annunciator will light to warn you that the output is unregulated.  
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Connecting Series 668xA Power Supplies To The Load  
ENERGY HAZARD. These power supplies can provide more than 240 VA at more than 2 V. If the  
output connections touch, severe arcing may occur resulting in burns, ignition or welding of parts. Do  
not attempt to make connections to live output circuits.  
€ Analog Connector  
ö + Output Bus Bar  
ó -Output Bus Bar  
ú + Local Sense Tap  
ì -Local Sense Tap  
÷ Signal Common  
A Option 601 cover required for bench installation  
Figure 4-5a. Series 668xA Rear Panel Output Connections  
Output Isolation  
Except for a high value (>1 MΩ) internal bleeder resistor, the output of the power supply is isolated from earth ground.  
Either output terminal may be grounded or an external dc voltage source may be connected between either output and  
ground. However, both output terminals must be kept within ±60 Vdc of ground.  
The earth ground terminal located near the output bus bars is a low-noise signal ground for  
convenience only. It is not designed to function as a safety ground.  
Load Considerations  
Capacitive Loads  
In most cases, the power supply will maintain stability with external load capacitors. However, large load capacitors may  
cause ringing in the supply’s transient response. It is possible that certain combinations of load capacitance, equivalent series  
resistance, and load-lead inductance will result in instability (see also “Stability” under “Remote Sensing”). If you need help  
solving a stability problem, contact an Agilent Service Engineer through your local Agilent Sales and Support Offices.  
If the output is rapidly programmed into capacitive loads, the power supply may momentarily cross into CC operation,  
thereby extending the CV programming time. When it crosses into CC mode, the supply's maximum slew rate is limited by  
the CC loop and is a function of the loop current compensation. This may be optimized for particular compensation. These  
momentary crossover situations, which are communicated via the status register, may increase programming times, but will  
not damage the power supply.  
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Inductive Loads  
Inductive loads present no loop stability problems in CV mode. In CC mode, inductive loads will form a parallel resonance  
with the power supply’s output capacitor, possibly causing current ringing in the load. For a given inductance, the power  
supply’s CC control loop can be made to stabilize the current. However, stabilizing the current for a very large load  
inductance creates a much slower mode crossover (CV to CC or vice versa) time. Thus, there is a tradeoff between mode  
crossover speed and inductive compensation. To allow an optimal solution for each load, a CC loop compensation switch is  
provided so the CC control loop can be optimized for a specific load inductance. See "Appendix E - Current Loop  
Compensation" for details.  
Battery Charging  
The power supply’s OVP circuit has a downprogrammer FET that discharges the power supply output whenever OVP trips.  
If a battery (or other external voltage source) is connected across the output and the OVP is inadvertently triggered or the  
output is programmed below the battery voltage, the power supply will sink current from the battery. To avoid this, insert a  
reverse blocking diode in series with the ⊕ output of the supply. Connect the diode cathode to the + battery terminal and  
the diode anode to the supply ⊕ output terminal. The diode will require a heat sink.  
Local Voltage Sensing  
For local sensing the +S and--S analog connector pins must be connected to the + and - bus bars (see Figure 4-5b). This is  
the default configuration as wired at the factory. Each sense lead is connected to the small, tapped hole nearest the  
corresponding output lead. Since local sensing does not compensate for voltage drops in the screw connections or load  
leads, local sensing should only be used in applications that require low output currents or where load regulation is not  
critical.  
Note  
If the sense terminals are left open, the voltage at the output bus bars will increase approximately 3 to 5%  
over the programmed value. The readback voltage will not reflect this increase because readback is  
measured at the sense terminals.  
Remote Voltage Sensing  
The dashed lines in the wiring diagrams illustrate remote voltage sensing. The remote sense terminals of the power supply  
are connected directly to the load rather than to the output bus bars. This allows the supply to automatically increase the  
voltage at the output bus bars to compensate for any voltage drop in the load leads, as well as to accurately read back the  
voltage directly from the load.  
Setting Up Remote Sense Operation  
You must connect the positive side of the load to the +S analog connector pin and the negative side of the load to the -S  
analog connector pin (see Figure 4-1). Connect the sense leads carefully so that they do not become open-circuited. If sense  
leads are left open during operation, the supply will regulate at the output bus bars instead of at the load. Remember to  
bundle or tie wrap the load leads to minimize inductance and reduce noise pickup.  
The sense leads are part of the supply’s feedback path and must be kept at a low resistance in order to maintain optimal  
performance. Connect the sense leads carefully so that they do not become open-circuited. If the sense leads are left  
unconnected or become open during operation, the supply will regulate at the output bus bars, resulting in a 3 to 5% increase in  
output over the programmed value.  
The maximum output voltage under remote sensing is reduced by the voltage drop in the load leads. See “Remote Sensing  
Capability” in Table 1-3b for further characteristics and a general formula for determining the extra degradation in the output  
due to voltage drop in the output leads.  
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OVP Considerations  
The power supply OVP circuit senses voltage near the output bus bars, not at the load. Therefore the signal sensed by the OVP  
circuit can be significantly higher than the actual voltage at the load. When using remote sensing, you must program the OVP  
trip voltage high enough to compensate for the voltage drop between the output bus bars and the load.  
Output Rating  
In remote sense applications, the voltage drop in the load leads subtracts from the available load voltage. As the power supply  
increases its output to overcome this voltage drop, the sum of the programmed voltage and the load-lead drop may exceed the  
power supply’s maximum voltage rating. This will not damage the supply, but may trip the OV protection circuit, which senses  
the voltage at the output bus bars. When the supply is operated beyond its rated output the performance specifications are not  
guaranteed, although typical performance may be good.  
Stability  
Using sensing under unusual combinations of load lead lengths and large load capacitances may cause your application to form  
a low-pass filter, which becomes part of the voltage feedback loop. The extra phase shift created by this filter can degrade the  
supply’s stability, resulting in poor transient response. In severe cases, it may cause oscillation. To minimize this possibility,  
keep the load leads as short as possible and tie wrap them together.  
In most cases, following these guidelines will eliminate problems associated with load lead inductance. However, if a large  
bypass capacitor is required at the load and load-lead length cannot be reduced, then a sense-lead bypass network may be  
needed to ensure stability (see Figure 4-5b).  
The voltage rating of the 33 µF capacitors should be about 50% greater than the anticipated load-lead drop. Addition of  
the 20 Ω resistors will cause a slight voltage rise at the remote sensing points. For utmost voltage programming accuracy,  
the supply should be recalibrated with the DVM at the remote sensing points (see “Appendix A - Calibration”). In  
addition, the sense protect resistors inside the power supply may have to be removed. (If you need help with a stability  
problem, contact an Support Engineer through your local Agilent Sales and Support offices.)  
€ Load Leads  
C1, C2 = 33µF  
ó Remote Sense Points  
Rl, R2 = 20 Ω, 1%  
C3 = Load bypass capacitor  
Figure 4-5b. Series 668xA Sense Lead Bypass Network  
Output Noise  
Any noise picked up on the sense leads may appear at the output of the supply and can adversely affect the voltage load  
regulation. Use shielded twisted pairs for the sense leads and route them parallel and close to the load leads. Ground the  
shields only at the power-supply end, utilizing the signal ground binding post. Do not use a shield as one of the sense  
conductors. Bundle or tie-wrap the load leads to minimize inductance and reduce noise pickup.  
Operating Configurations  
Figure 4-5c through Figure 4-5e show the various configurations for connecting to the load. Figure 4-5f shows how to  
connect an external voltage source for analog programming.  
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Connecting One Power Supply to a Single Load  
Figure 4-5c shows how to connect a single power supply to one load. Keep output load leads close together (small loop  
area) to obtain a low inductance and low impedance connection to the load. If you wish to use remote sensing, connect the  
sense leads at the load as shown in the figures.  
€ Analog Connector  
ú Lockwasher  
ó Load Connection  
÷ Flatwasher  
ì Load  
ø 3-8 inch bolt  
ö Nut  
A Connect for remote sensing (optional)  
B Connect for local sensing (default)  
Figure 4-5c. Series 668xA Single Load Connection (Remote Sensing Optional)  
Note  
If you are using a bench application requiring the Option 601 Output Connector Kit, be sure to consult  
the instructions supplied with the kit.  
Connecting One Power Supply to Multiple Loads  
Figure 4-5d shows how to connect a single power supply to more than one load. When connecting multiple loads to the  
power supply with local sensing, connect each load to the output bus bars with separate connecting wires. This minimizes  
mutual coupling effects and takes full advantage of the supply’s low output impedance. Keep each pair of load wires as  
short as possible and twist or bundle them to reduce lead inductance and noise pickup.  
€Load  
óLoad Connection  
ìAnalog Connector  
A Connect for remote sensing (optional)  
Connect for local sensing (default)  
B
Figure 4-5d. Series 668xA Multiple Load Connection (Remote Sensing Optional)  
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Connecting Supplies in Auto-Parallel  
Auto-Parallel Wiring (Figure 4-5e). Figure 4-5e shows how power supplies can be auto-paralleled for increased current  
output. Up to three supplies can be connected for auto-parallel operation. Use heavy enough load leads so that the absolute  
voltage difference between the ⊕ output terminals of the "master" supply and the ⊕ output terminal of the first "slave"  
supply is kept under 2 V at rated current. This also applies to the voltage difference between the ⊕ output terminals of the  
first and second "slave" supplies. If remote sensing is necessary, connect the remote sense terminals of the "master" supply  
as shown by the dashed lines in Figure 4-5e. See "Remote Voltage Sensing" for more information.  
Auto-Parallel Programming. Only the first supply in the series (the "master") is programmed; the supplies that are  
connected to the master automatically track its output. However, the voltage and OVP settings of the slave supplies must  
be set higher than the operating voltage of the master supply. This ensures that the slave supplies will operate in CC mode  
when tracking the output of the master supply. Be sure to set the output current of the slave supplies to zero, because all  
current programming inputs (GPIB, front panel, and external voltage) are additive. Functions such as status, voltage  
readback, and current readback can still be read back individually for each supply.  
If a "slave" supply experiences a desired shutdown condition (such as caused by overtemperature or overcurrent), it does  
not automatically shut down all other supplies. You must first enable remote inhibit (RI) and discrete fault indicator (DFI)  
operation. It is recommended that you use the RI and DFI functions to automatically shut down all supplies whenever one  
supply experiences a shutdown condition. See "Fault/Inhibit Operation" in "Appendix D - Digital Port Functions" for  
wiring information and "Questionable Status Group" in the "Programming Guide" for programming information.  
€ Analog Connector  
ó Slave Supply  
ì Master Supply  
öProgram only the master. Set slave output and OVP voltage slightly higher than the master to ensure that slave stays in  
CC mode  
ú Load  
A Only local sensing permitted  
÷ Load Connection  
Connect for remote sensing (optional)  
B
Figure 4-5e. Series 668xA Auto-Parallel Connection (Remote Sensing Optional)  
Connecting Supplies in Series  
Floating voltages must not exceed ± 60 Vdc. No output terminal may be more than 60 V from chassis  
ground.  
Figure 4-5f illustrates how power supplies can be connected in series for increased voltage capability. Series connections  
are straightforward in this case.  
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Program each power supply as an independent supply. If two supplies are used in series operation, each supply can be  
programmed to deliver 50% of the total output voltage. Set the current limit of each power supply to the maximum that the  
load can handle without damage.  
If one supply experiences a desired shutdown condition (such as caused by overtemperature or overcurrent), it does not  
automatically shut down the other supply. You must first enable remote inhibit (RI) and discrete fault indicator (DFI)  
operation. It is recommended that you use the RI and DFI functions to automatically shut down both supplies whenever one  
supply experiences a shutdown condition. See "Fault/Inhibit operation" in "Appendix D - Digital Port Functions" for wiring  
information and "Questionable Status Group" in the "Programming Guide" for programming information.  
€ Analog Connector  
ö Program each supply for full load current and 1/2 the load voltage  
A Connect for remote sensing (optional) B Connect for local sensing (default)  
WARNING  
ó Load  
ì Load Connection  
FLOATING VOLTAGES MUST NOT EXCEED ±60 VDC. NO OUTPUT TERMINAL MAY  
BE MORE THAN 60 V FROM CHASSIS GROUND.  
Figure 4-5f. Series 668xA Series Connection (Remote Sensing Optional)  
Each power supply has a reverse voltage protection diode across its output. If the fan in one of the  
series power supplies shuts down for any reason (such as a fan circuit defect or loss of ac power), the  
supply may severely overheat due to current forced through its reverse current diode by the functioning  
supply. This possibility can be eliminated by use of the Rl/DFI functions previously noted. Also, if a  
reverse voltage is applied across a functioning supply, it has no control over the current conducted  
through this diode. To avoid damaging the supply, never connect it in such a way that a reverse voltage  
can force it to conduct current in excess of the supply’s maximum rated current. (see Table 1-4b)  
External Voltage Control  
The setup shown in Figure 4-5g allows an external dc voltage to program the power supply output. A zero-to-full scale  
voltage applied to the voltage programming input produces a proportional zero-to-full scale output voltage. The voltage  
programming source is referenced to the programming Common P (↓P) terminal. A zero-to-full scale voltage applied to  
one of the current programming inputs produces a proportional zero-to-full scale output current. See Figure 4-1 for an  
explanation of these programming input connections.  
Wiring Considerations (Figure 4-5g)  
The input impedance of the analog input is over 30 kΩ. If the output impedance of your programming source is not negligible  
with this, programming errors will result. Larger output impedances result in proportionally greater errors.  
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1 = Voltage programming source 0 to -5 V  
2 = Current programming source 0 to +5 V  
3 = Current programming source 0 to -5 V  
4 = Current programming source floating 0 to 5 V  
* Maximum potential between -IP and ↓P or between +IP and ↓P is ±15 V  
Figure 4-5g. Series 668xA Analog Programming Connections  
Programming  
Note from Figure 4-1 that you have three options for programming the current. You can use a voltage source that is positive,  
negative, or floating with respect to Common P. Do not exceed +15 V with respect to Common P.  
Make certain that the common connection for your voltage programming source is isolated from the load.  
Failure to do this may cause damage to the power supply.  
The effect of the analog programming source is always summed with the values programmed over the GPIB or from the front  
panel. The voltage source can act alone only if you set the other program sources to zero. Keep the total programmed setting of  
the supply (the analog input summed with the GPIB or front panel settings) at or under the output ratings specified in Table 1-3a.  
Exceeding the output ratings will not damage the supply, but it may not be able to regulate its output the higher levels. If this  
happens, the Unr annunciator will light to warn you that the output is unregulated.  
Controller Connections  
Figure 4-6 shows two basic ways of connecting your power supply to a controller. They are "linked" and "stand-alone  
configurations.  
Stand-Alone Connections  
See Figure 4-6A. Each stand-alone power supply has its own GPIB bus address. Stand-alone power supplies may be  
connected to the bus in series configuration, star configuration, or a combination of the two. You may connect from  
1 to 15 stand-alone power supplies to a controller GPIB interface.  
Linked Connections  
See Figure 4-6B. Up to 16 power supplies may be used at a single GPIB primary bus address by making linked  
connections. (You cannot use linked connections if you intend to program power supplies with the Compatibility  
Language - see the power supply “Programming Guide".)  
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■ The first power supply in a linked connection is a "direct supply" connected to the controller via a GPIB cable. The  
direct supply is the only supply connected directly to the bus and has a unique primary bus address.  
■ The remaining power supplies are "linked supplies” connected to the direct supply via a serial-link cable. Each  
linked supply has a unique secondary GPIB address and derives its primary address from the direct supply. You may  
connect from 1 to 15 linked supplies to each direct supply.  
Note  
The power supply is shipped from the factory with its GPIB address set to 5. The power supply primary  
and secondary addresses can be changed from the front panel as described in "Chapter 2 - Remote  
Programming" of the "Programming Guide". For power supply GPIB interface capabilities, see Table  
1-5 in Chapter 1 of this guide.  
€
ó
ì
ö
ú
÷
ø
A
From 1 to 16 direct supplies may be connected to 1 controller GPIB interface.  
Tighten connector thumbscrews by hand. Do not use a screwdriver.  
Do not stack more than 3 connectors on a GPIB receptacle.  
GPIB cable (see Accessories in Chapter 1)  
From 1 to 15 linked supplies may be connected to 1 direct supply.  
Either receptacle (Jl or J2) may be used as an input or an output.  
Serial Link Cable (see Accessories in Chapter 1), 2 meters. 1 is supplied.  
Maximum total length of all GPIB cables (including controller) not to exceed 20 meters.  
Use caution with individual lengths over 4 meters.  
B
Maximum total length of all serial cables not to exceed 30 meters.  
NOTES:  
1. A direct power supply is connected to the controller interface and must have a unique primary GPIB bus address.  
2. The stand-alone configuration uses only direct supplies connected to the controller interface.  
3. The linked configuration uses 1 or more linked power supplies connected to each direct supply. Each linked supply has  
a unique secondary GPIB bus address and derives its primary address from the direct supply.  
Figure 4-6. Controller Connections  
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5
Front Panel Operation  
Introduction  
This chapter shows you how to operate the front panel. It is assumed that you are familiar with the turn-on checkout  
procedure in Chapter 3. That chapter describes how to perform basic power supply functions from the control panel.  
operations that you can perform are:  
■
■
■
■
■
■
■
■
■
■
Enabling or disabling the power supply output.  
Setting the output voltage and current.  
Monitoring the output voltage and current.  
Setting the overvoltage protection (OVP) trip point.  
Enabling the overcurrent protection (OCP) circuit.  
Saving operating states in nonvolatile memory.  
Recalling operating states from nonvolatile memory.  
Setting the power supply GPIB bus address.  
Displaying error codes created during remote operation.  
Enabling local (front panel) operation.  
Note  
You also can calibrate the power supply from the front panel (see Appendix A).  
Getting Acquainted  
The front panel is summarized in Figure 5-1 and Table 5-1. Note that the panel is organized as follows:  
€ LCD display (including annunciators)  
ó Output VOLTAGE and CURRENT rotary (RPG) knobs  
ì SYSTEM keypad  
ö FUNCTION keypad  
ú ENTRY keypad  
÷ Power (LINE) switch  
ø Fuse LED (Series 668xA only)  
í DEW LED (Series 668xA only)  
Some keys have two functions. For example, the System  
key (3, Figure 5-1) can be used either to recall a stored  
operating state or to  
(store) an operating state. The first operation is shown on the key and the second (shifted)  
operation is shown in blue above the key. In order to do a shifted operation, first press the solid blue key, which is  
unlabeled but shown throughout this manual as  
.
For example, for a recall operation, press the recall key  
. When you do this, the Shift annunciator will light to remind you that the  
key. In this chapter, such a shifted operation may be shown simply as  
. For a save operation, press the save key, which is  
key is now functioning as  
the  
.
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Figure 5-1. Front Panel Controls and Indicators  
Table 5-1. Front Panel Controls and Indicators (see Figure 5-1)  
Function or Indication  
Control or  
Indicator  
€ Display  
VOLTS  
AMPS  
Shows present output voltage of the power supply.  
Shows present output current of the power supply.  
Status Annunciators  
CV  
CC  
Unr  
Dis  
The power supply is in constant-voltage mode.  
The power supply is in constant-current mode.  
The power supply output is unregulated (output is neither CV or CC).  
The power supply output is disabled.  
OCP  
Prot  
The overcurrent protection function is enabled.  
A protection circuit has caused the power supply to shut down. (Press  
An error has been generated as a result of remote operation. (Press  
The power supply is in calibration mode.  
to determine the reason.)  
to display the error code).  
Err  
Cal  
Shift  
The shift key  
has been pressed.  
Rmt  
Addr  
SRQ  
The power supply is in the remote mode (controlled over the GPIB).  
The power supply is addressed to listen or talk.  
The power supply is requesting service from the controller.  
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Table 5-1. Front Panel Controls and Indicators (continued)  
óOutput Rotary Controls  
Voltage  
Current  
Rotate clockwise to increase output voltage or program setting. Use to rapidly set an approximate output  
value (see  
Rotate clockwise to increase output current or program setting. Use to rapidly set an approximate current  
value (see and keys).  
and  
keys).  
ì SYSTEM Keys  
When the power supply is under remote control, press to enable local operation. This control can be  
defeated by a lock-out command over the GPIB  
Press to display the power supply’s GPIB address. You can change the address with theENTRY keys  
Use to display error codes generated during remote operation. (Select by pressing  
.)  
Use to restore a previously saved power supply state. Use ENTRY keys  
the Series 668xA) to specify which location to recall. (Select by pressing  
through  
(
through  
on  
.)  
Note: Location 0 may contain the power supply turn-on state. See "Turn-on operation" in this chapter.  
Use to save the power supply’s present state to nonvolatile memory. (Select by pressing  
.)  
Use ENTRY keys to specify the location where you want to store the state. You may use locations  
through  
(
through  
on the Series 668xA).  
This unlabeled blue key is the Shift key. Press to access the shifted (alternate) key functions.  
ö Function Keys  
Press to enable or disable the power supply output. This key toggles between the two states. The disabled  
state programs the output to the *RST voltage and current settings (see the Programming Guide).  
Press to display the output voltage setting. After pressing  
change the value.  
, you may use the ENTRY keys to  
Press to display the output current setting. After pressing  
change the value.  
, you may use the ENTRY keys to  
Press to display the OV trip voltage setting. After pressing  
, you may use the ENTRY keys to change  
the value.  
When the Prot annunciator is on, press  
to see which protection circuit caused the power supply  
to shut down. Response can be OC (overcurrent), OT (overtemperature), or OV (overvoltage). If no  
protection circuit has tripped, the display will show dashes (- - - -).  
Press this key to reset the protection circuit. If the condition that caused the circuit to trip has been  
removed, the Prot annunciator will go off.  
Press to enable or disable the power supply OCP trip circuit. This key toggles between the two states.  
which are indicated by the OCP annunciator.  
ú ENTRY Keys  
Press to increment the output voltage in the CV mode, or to increase the voltage setting after you have  
pressed the  
key. 3  
Press to decrement the output voltage in the CV mode, or to decrease the voltage setting after you have  
pressed the  
key.3  
Press to increment the output current in the CC mode, or to increase the current setting after you have  
pressed the  
key.3  
Press to decrement the output current in the CC mode, or to decrease the current setting after you have  
pressed the  
key.3  
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Table 5-1. Front Panel Controls and Indicators (continued)  
ú ENTRY Keys (continued)  
Press to select numerical values .  
thru  
Press to enter a minus sign.  
Press to delete the last keypad entry. Use this key to remove one or more incorrect digits before they are  
entered.  
3
These four entry keys operate in two modes. Press and release for a single minimal change as  
determined by the programming resolution (see Table 1-2 in Chapter l). Press and hold for an increasingly  
rapid output change.  
Press to delete an entire keypad entry and return to the meter mode. Use this key to exit from a value  
before it is entered.  
Press to enter a value or to accept an existing value and return the display to the meter mode.  
The remaining shifted keys are for calibration (see "Appendix A - Calibration").  
÷ Check Fuses LED and ø Dew LED (Series 668xA only)  
Check Fuses  
Dew  
If one or more of the line fuses opens, this LED lights. (see "In Case of Trouble" in Chapter 3).  
If you turn on the power supply when its inside humidity is≈ 100%, the power will not go on and this  
LED will light (see "In Case of Trouble" in Chapter 3).  
Programming The Output  
Introduction  
Important  
These instructions show how to program a single power supply. There are special considerations when  
you have two or more supplies connected in series or in autoparallel. See "Chapter 4 - User Connections  
and Considerations".  
The power supply accepts values directly in volts and amperes. Values will be rounded off to the nearest multiple of the  
output resolution (see “Average Resolution" in Table 1-2 of Chapter 1). If you attempt to enter a value not in a valid range,  
the entry will be ignored and OUT OF RANGE appears on the display.  
Figure 5-2 shows the general response of a typical power supply. Unless directed otherwise, always keep the output voltage  
and current within the boundaries of its operating line for the specified mode of operation (CV or CC).  
Establishing Initial Conditions  
Set the power supply to its *RST state by pressing  
. This state was stored in location 0 at the factory. If it  
has since been changed, you can restore it as directed under “Turn-on Conditions”, later in this chapter. *RST results in the  
following operating conditions:  
■
■
■
■
■
Zero voltage output.  
Minimal current output.  
Output disabled (Dis annunciator on).  
Overcurrent protection off (OCP annunciator off).  
Protection circuits cleared (Prot annunciator off).  
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Figure 5-2. Typical Power Supply Operating Curve  
Programming Voltage  
To program the output for 4.5 volts, proceed as follows:  
■
■
Press  
Press  
key  
. The display will change from meter mode to indicate VOLTS.  
. If you discover a mistake before pressing , erase the incorrect value with the backspace  
.
■
■
The display will return to the meter mode and indicate 0.000 volts.  
Press to enable the output (Dis annunciator turns off). The VOLTS display will indicate 4.500 volts.  
Note  
The power supply must be programmed for a minimal current in order to increase the output voltage  
beyond zero. Normally, there is sufficient idle current to do this. If the power supply does not respond or  
the CC annunciator turns on, go to “Programming Current” and set the current to a small value.  
■ Now raise the voltage by pressing  
voltage programming resolution) each time you press the key and increases rapidly as you hold down the key. To lower  
the voltage, press  
.Note that the voltage increases by a specific increment (depending on the  
.
■ Try raising and lowering the voltage by rotating the Voltage control clockwise and then counterclockwise. Note how the  
output responds as compared to using the Entry keys.  
Try to program a voltage greater than the VMAX for your supply (see "Supplemental Characteristics" for your particular  
model in Chapter 1). Note that the display shows OUT OF RANGE.  
Programming Overvoltage Protection  
Overvoltage protection guards the load against voltages that reach a specified value above the programmed output voltage.  
Setting the OVP Level  
Assuming that you have programmed the power supply for 4.5 volts, you can set the OVP level to 4.8 volts as follows:  
■ Press  
. The display will change from meter mode to indicate 0V, followed by the present OVP value.  
■ Press  
.
■ The display will return to the meter mode and indicate the output (4.500 volts).  
■ Press  
again. The display will now indicate 0V 4 . 800.  
■ Press  
to return to the meter mode.  
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Checking OVP Operation  
Assuming the above operating conditions (voltage programmed to 4.5 V and OVP programmed to 4.8 V), trip the OVP  
circuit as follows:  
■ Gradually increase the output voltage by pressing  
voltage to drop to zero and the Prot annunciator to go on.  
until the OVP circuit trips. This will cause the output  
■ There now is no power supply output due to an overvoltage condition.  
■ To verify this, press  
and observe that the display indicates 0V. This shows that the protection circuit tripped  
due to an overvoltage condition.  
Clearing The OVP Condition  
With the OVP tripped, return to the meter mode and try to clear the condition by pressing  
. Nothing will appear  
to happen because the OV trip voltage is still below the programmed output voltage. Thus, as soon as the circuit is cleared,  
it trips again. You can clear the OV condition by:  
■
■
Lowering the output voltage below 4.8 (the OV setting), or  
By raising the OV trip voltage above the output voltage setting.  
Try either of these methods. Now when you press  
return to normal.  
, the Prot annunciator will turn off and the output voltage will  
Programming Current  
ENERGY HAZARD. Some power supplies (Series 668xA) can provide more than 240 VA at more  
than 2 V. If the output connections touch, severe arcing may occur resulting in burns, ignition or  
welding of parts.  
You may program the power supply current without a load, but must have a load in order to draw output current. These tests  
assume you have the load connected in accordance with the information in “Chapter 4 - User Connections and  
Considerations”. If you do not have a load on the power supply, you may connect a short across the output terminals as  
described in “Chapter 3 - Turn-on Checkout”.  
The example will program a low current. (You may later increase the output current to the levels you will expect to use.) To  
program the output current to 1.3 amperes, proceed as follows:  
■
■
Disable the output by pressing  
Program the voltage by pressing  
. The Dis annunciator will turn on.  
.
■
■
Press  
Press  
key  
. The display will change from meter mode to indicate AMPS.  
. If you discover a mistake before pressing erase the incorrect value with the backspace  
.
■
■
■
The display will return to the meter mode and indicate up to 0 . 000.  
Press  
to enable the output. Dis will turn off and the display will indicate VOLTS 5 . 000 AMPS 1. 300.  
Now increase the current by pressing  
. Note that the current increases by a specific increment (depending on  
the current programming resolution) each time you press the key and increases rapidly as you hold down the key. To  
decrease the current, press  
.
■
Try increasing and decreasing the current by rotating the Current knob clockwise and counterclockwise. Note how the  
output responds as compared to using the Entry keys.  
Disable the output by pressing  
. The Dis annunciator will turn on. Now try to program a current greater than  
the IMAX for your supply. Note that the display shows OUT OF RANGE.  
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Programming Overcurrent Protection  
When enabled, overcurrent protection removes the power supply output whenever it goes into CC operation. This prevents  
the supply from indefinitely supplying the full programmed current to the load.  
Setting The OCP Protection  
To activate overcurrent protection, press  
. The OCP annunciator will light and power supply will continue to operate  
normally until it is forced into CC operation. If that occurs, the OCP circuit will trip and the power supply will remove its  
output.  
Checking OCP Operation  
The easiest way to check this operation at any specified current is to increase the load current beyond the programmed  
current value and, if necessary, decrease the programmed voltage. This will force the power supply into the CC mode (see  
Figure 5-2). When OCP trips, the Prot annunciator will light and the power supply output will drop to zero.  
There is now no power supply output due to an overcurrent condition. To verify this, press  
and observe that the  
display indicates OC.  
Clearing The OCP Condition  
With the OCP tripped, return to the meter mode and try to clear the condition by pressing  
. Nothing will appear to  
happen because the reason for the condition has not been removed. Thus, as soon as the circuit is cleared, it trips again. You  
can clear the OC condition by:  
■ Increasing the load resistance to lower the output current below the programmed current value, or  
■ By raising the programmed current to a value above that required by the load.  
Clear the fault by either of the above methods. Then clear the OCP circuit by pressing  
go off and the power supply output will be restored to normal.  
. The Prot annunciator will  
If desired, you can also restore the output by disabling the OCP function (press  
to turn off the OCP annunciator).  
This restores the output but does not clear any condition that may have caused OCP to trip.  
Note  
Under certain conditions, the OCP circuit may fail to clear because load demand occurs before the power  
supply has time to build up the required output current capacity. In such cases, disable the output (press  
before clearing the OCP circuit). After OCP is cleared, enable the power supply output.  
CV Mode VS. CC Mode  
Once you program a voltage (VS) and a current (IS) in Figure 5-2, the power supply will try to maintain itself in either CV or  
CC mode, depending on the impedance of the load (RL). If the load demands less current than Is, operation will be in CV  
mode with the voltage maintained at Vs. The output current will be at some value below Is as determined by VS ÷ RL.  
If the current increases beyond IS (see RL2), the supply will switch to CC mode by varying its output voltage to maintain a  
constant current value of Is. As more current is demanded, the voltage decreases to maintain the increased current level. If  
the load current increases to the maximum output of the power supply, the output voltage will be maintained at a near-zero  
level.  
Front Panel Operation 89  
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Unregulated Operation  
If the power supply goes into a mode of operation that is neither CV nor CC, the Unr annunciator will light. An unregulated  
condition limits the output current to a value that is safe for the power supply. Some unregulated states occur so briefly that  
they do not turn on the Unr annunciator, but they may set the UNR status bit during remote operation (see the power supply  
“Programming Guide”). One condition that can cause a noticeable unregulated state is low ac line voltage.  
Saving and Recalling Operating States  
You can save programming time by storing up to 5 (up to 4 with Series 668xA supplies) operating states in nonvolatile  
memory. The front panel programming parameters that are saved are:  
■
■
Output voltage, Output current, OVP voltage.  
OCP state (on or off), Output state (enabled or disabled).  
Note  
More power supply parameters are saved in remote operation. See the power supply “Programming Guide”.  
As an example, set up the following state:  
■
■
Voltage = 4 V Current = 5 A OVP voltage = 4.5 V.  
OCP = on (OCP annunciator on) Output = off (Dis annunciator on).  
Save the above state to location 1 by pressing  
. Now set up the following state:  
■
■
Voltage = 4.5 V Current = 2.5 A OVP voltage = 5 V.  
OCP = off (OCP annunciator off) Output = on (Dis annunciator off).  
Save the above state to location 2 by pressing  
.
Restore the first state by pressing  
and verify the parameters. Restore the second state by pressing  
. Note how the power supply is automatically programmed each time.  
Turn-On Conditions  
Whenever you apply power to a new power supply it automatically turns on in a safe reset state with the following  
parameters:  
off  
maximum  
0
minimum*  
off  
*Minimum is the *RST value specified in Table 3-1 in the Programming Guide.  
It is recommended that you leave the turn-on conditions as programmed. However, you may change them if you wish. To do  
this, proceed as follows:  
1. Set up the power supply to the state you want when it is turned on.  
2. Store that state to location 0.  
3. Turn off the power supply.  
4. Hold in the key and turn the power supply back on. The display indicates RCL 0 PWR-ON to verify that the power  
supply has configured its turn-on state to that stored in location 0.  
5. From now on the supply will always turn on to the state defined in location 0.  
90 Front Panel Operation  
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Whenever you wish, you can return the power supply to the original factory reset state. To do this, simply hold down the  
key when you turn on the supply. The display indicates RST POWER-ON to verify that the power supply has configured  
its turn-on state to the original reset state. From now on it will continue to turn on in that state.  
Setting The GPIB Address  
Types of Power Supply GPIB Addresses  
Figure 4-6 in Chapter 4 shows the ways the power supply can be connected to the GPIB bus. You can set up the GPIB  
address in one of three ways:  
1. As a stand-alone supply (the only supply at the address). It has a primary address in the range of 0 to 30. For example:  
5 or 7.  
2. As the direct supply in a serial link. It is the only supply connected directly to the GPIB bus. The primary address is  
unique and can be from 0 to 30. It is entered as an integer followed by a decimal separator. The secondary address always  
is 0, which may be added after the primary address. If the secondary address is omitted, it is assumed to be 0. For  
example: 5.0 or 7.  
3. As a linked supply in serial link. It gets its primary address from the direct supply. It has a unique secondary address  
that can be from l to 15. It is entered as an integer preceded by a decimal separator. For example: .l or .12  
When you enter a secondary address, leading zeros between the decimal separator and the first digit are ignored. For  
example, .1, .01, and .001 are accepted as secondary address 1 and displayed as 0.01. Zeros following a digit are not  
ignored. Thus, .10 and .010 are both accepted as secondary address 10 and displayed as 0. 10.  
Changing the Power Supply GPIB Address  
Use the  
key and numerical keypad for entering addresses. The power supply is shipped with a 5 stand-alone  
address as the default. The general procedure for setting an address is:  
Action  
Display Shows  
Press  
Current address  
Press new address keys  
Press  
New address replaces numbers on the display  
Display returns to meter mode  
If you try to enter a forbidden number, ADDR ERROR is displayed.  
The following examples show how to set addresses:  
To set stand-along primary address 6, press  
To set direct supply primary address 6, press  
To set linked secondary address 1, press  
.
.
.
To set linked secondary address 12, press  
.
Note  
The power supply display will reset (recall the state in location 0) whenever you change between the  
following types of GPIB addresses:  
• a stand-alone primary address and a direct primary address.  
• a direct primary address and a secondary address.  
Front Panel Operation 91  
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A
Calibration  
Introduction  
The power supply may be calibrated either from the front panel or from a controller over the GPIB. The procedures given  
here apply to all models.  
Important  
These instructions do not include verification procedures. If you need to perform verification as a  
erequisite to or as part of your calibration procedure, see “Appendix B - Verification”.  
Equipment Required  
The equipment listed in Table A-1, or equivalent, is required for calibration.  
Table A-1. Equipment Required For Calibration  
Equipment  
Characteristics  
D-c accuracy 0.005%, 6 digits  
Recommended Model  
Agilent 3456A or 3458A  
Voltmeter  
Shunt resistor  
Agilent 6641A, 51A, 52A  
Agilent 6642A, 43A, 44A, 45A,  
6643A, 54A, 55A  
Guildline 9230/100  
Guildline 9230/15  
100 A, 0.01 Ω, 0.04%, 100 W  
15 A, 0.1 Ω, 0.04%, 25 W  
Agilent 6671A  
Agilent 6672A, 73A, 74A, 75A  
Agilent 6680A, 81A  
Guildline 9230/300  
Guildline 9230/300  
Burster 1280S  
300 A, 0.001 Ω, 0.04%,100 W  
300 A, 0.001 Ω, 0.04%, 100 W  
1000 A, 0.1 mΩ, 0.05%  
Agilent 6682A, 83A, 84A  
Guildline 9230/300  
300 A, 0.1 mΩ, 0.05%  
For Calibration Over the GPIB  
GPIB Controller  
HP Vectra (or IBM compatible) with GPIB Interface, or HP BASIC series  
General Procedure  
Because the power supply output must be enabled during calibration, voltages or currents  
hazardous to personnel and/or damaging to equipment can appear at the output terminals.  
ENERGY HAZARD. Series 668xA supplies can provide more than 240 VA at more than 2 V. If the  
output connections touch, severe arcing may occur resulting in burns, ignition or welding of parts. Do  
not attempt to make connections to live output circuits.  
Parameters Calibrated  
The following parameters may be calibrated:  
•
•
•
Output voltage.  
Output voltage readback.  
Overvoltage protection (OVP).  
Calibration 93  
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•
•
•
Output current.  
Output current readback.  
Current monitor input IM (Series 668xA only).  
You do not have to do a complete calibration each time. If appropriate, you may calibrate only the voltage or current and  
proceed to "Saving the Calibration Constants". However, for Series 668xA supplies, the following sequences must be  
followed:  
•
•
Calibrate voltage before OVP.  
Calibrate the current monitor input before current output.  
Test Setup  
Figure A-1 shows the test setups required for voltage and current calibration for each power supply series.  
Front Panel Calibration  
Eight shifted keys and the Entry keypad are used for calibration functions (see "Chapter 5 - Front Panel Operation” for  
explanations of shifted keys and the Entry keypad). The following procedures assume you understand how to operate front  
panel keys.  
Entering the Calibration Values  
Follow the steps in Table A-2 for entering calibration values.  
Saving the Calibration Constants  
Storing calibration constants overwrites the existing ones in nonvolatile memory. If you are not  
absolutely sure you want to permanently store the new constants, omit this step. The power supply  
calibration will then remain unchanged.  
To replace any existing calibration constants with ones you have just entered, press  
.
CAL SAVED then appears on the display.  
Disabling the Calibration Mode  
To disable the calibration mode, press  
. The display will return to meter mode with the Cal annunciator off.  
Changing the Calibration Password  
The factory default password is the model number of your supply, such as 6671. You can change the calibration password  
only when the power supply is in the calibration mode (which requires you to enter the existing password). Proceed as  
follows:  
1. Press  
.
2. Enter the new password from the keypad. (You can use up to six integers and an optional decimal point.) If you want  
to operate without requiring any password, change the password to 0 (zero).  
3. AGAIN will appear on the display. Enter the password a second time.  
4. When OK is displayed, the new password has been accepted.  
94 Calibration  
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Figure A-1. Calibration Test Setup  
Calibration 95  
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Table A-2. Typical Front Panel Calibration Procedure  
Action  
Display Response  
PASWDl  
Enabling the Calibration Mode  
1. Begin calibration by pressing  
.
2. Enter calibration password from Entry keypad.  
If password is correct the Cal annunciator will come on.  
If password is incorrect, an error occurs2.  
PASSWD ERROR  
Note: The initial (factory-default) password is the model number of the power supply,  
but it can be changed (see "Changing the Password" in Appendix A - Calibration).  
Entering Voltage Calibration Values  
1. Make certain the DVM is the only load on the power supply.  
(Meter mode)  
VRDG1  
WRONG MODE  
(Meter mode)  
VRDG2  
2. Select the first calibration point by pressing  
.
If the power supply is not in CV mode, an error occurs3  
3. Read the DVM and use the Entry keypad to enter the first voltage value.  
4. Select the second calibration point by pressing  
again.  
(Meter mode)  
5. Read the DVM and use the Entry keypad to enter the second voltage value.  
Note: If one of the entered values is not within acceptable range, an error occurs.  
The power supply is now holding the new voltage calibration constants in RAM.  
CAL ERROR  
Calibrating the OVP Trip Point  
1. Make certain the voltage has been calibrated and there is no load on the power supply.  
(Meter mode)  
2. Select OVP calibration by pressing  
.
OVPCAL  
CAL COMPLETE  
NOT CV MODE  
DOES NOT CAL  
3. Wait for the power supply to compute the OVP calibration constant.  
If the supply goes unregulated or into CC mode during OVP calibration, an error occurs.  
If the computed constant is out of acceptable range, an error occurs.  
The power supply is now holding the new OVP calibration constant in RAM.  
Entering Current Calibration Values  
1. Make certain appropriate shunt resistor (see Table A-l) is the only load on the power supply.  
(Meter mode)  
IRDG1  
WRONG MODE  
(Meter mode)  
2. Select the first calibration point by pressing  
.
If the power supply is not in CC mode, an error occurs.4  
3. Wait for DVM reading to stabilize. Then read DVM and compute the first current value  
(DVM reading ÷ shunt resistance).  
(Meter mode)  
IRDG2  
4. Use Entry keypad to enter the first current value.  
5. Select second calibration point by pressing  
again.  
6. Wait for DVM reading to stabilize. Then read DVM and compute the second  
current value (DVM reading ÷ shunt resistance).  
7. Use Entry keypad to enter the second current value.  
(Meter mode)  
(Meter mode)  
CAL ERROR  
CAL COMPLETE  
Note: If the entered value is not within acceptable range, an error occurs.  
Wait for the power supply to compute the new current calibration constants, which will be  
stored in RAM.  
1. If CAL DENIED appears, then an internal jumper has been set to prevent the calibration from being changed. (See the  
Service Manual.)  
2. If the active password is lost, the calibration function can be recovered by moving an internal jumper that defeats  
password protection. However, this also will change all calibration constants to their factory-default values. (For more  
information, see the Service Manual.)  
3. Program the output current to 10% of its rated output*  
4. Program the output voltage to l0% of its rated output*  
* See applicable Output Ratings in "Chapter 1- General Information"  
96 Calibration  
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Table A-2. Typical Front Panel Calibration Procedure (continued)  
Action  
Display Response  
Calibrating Current Monitor (IM) (Series 668xA Only)  
If you perform this calibration, then you must recalibrate the current output.  
1. Make certain the appropriate shunt resistor (see Table A-1) is the only load on the power  
supply.  
(Meter mode)  
IMON CAL  
WRONG MODE  
(Meter mode)  
2. Select IMN calibration by pressing  
If the power supply is not in CC mode, an error occurs.4  
3. Wait for DVM reading to stabilize. Then read DVM and compute the current value  
(DVM reading ÷ shunt resistance).  
(Meter mode)  
CAL ERROR  
CAL COMPLETE  
4. Use Entry keypad to enter the current value.  
Note: If the entered value is not within acceptable range, an error occurs.  
Wait for the power supply to compute the new current calibration constants, which will be  
stored in RAM.  
CAL ERROR  
If the constant is not within acceptable range, an error occurs.  
4.  
Program the output voltage to 10% of its rated output*  
*See applicable Output Ratings in “Chapter 1- General Information”  
Recovering From Calibration Problems  
You can encounter serious calibration problems if you cannot determine a calibration password that has been changed or the  
power supply is severely out of calibration. There are jumpers inside the power supply that permit the calibration password  
to be defeated and allow the original factory calibration constants to be restored. These jumpers are explained in the Service  
Manual.  
Calibration Error Messages  
Error messages that can occur during calibration are shown in Table A-3.  
Table A-3. GPIB Calibration Error Messages  
Error  
No.  
Meaning  
Error  
No.  
6
7
Meaning  
1
2
3
4
5
CAL jumper prevents calibration1  
CAL password is incorrect  
CAL mode is not enabled  
Incorrect computed readback constants  
Incorrect computed programming  
constants  
Wrong CAL command sequence  
Incorrect state (CV/CC) for this command  
1 This is a hardware disable. See the power supply  
Service Manual.  
Calibration 97  
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Calibration Over The GPIB  
You can calibrate the power supply by using SCPI commands within your controller programming statements. Be sure you  
are familiar with calibration from the front panel before you calibrate from a controller. The SCPI calibration commands are  
related to the front panel calibration controls as follows:  
Front Panel  
Command  
Corresponding SCPI  
Command  
Front Panel  
Command  
Corresponding SCPI  
Command  
CAL:STAT {ON|1},<password>  
CAL:VOLT:PROT  
CAL:STAT {OFF|0}  
CAL:PASS <NRf>  
CAL:CURR:LEV {MIN|MAX}  
CAL:CURR[:DATA] <NRf>  
CAL:CURR:MON<newline>  
CAL:CURR:DATA <NRf>  
CAL:SAVE  
CAL:VOLT:LEV {MIN|MAX}  
CAL:VOLT[:DATA] <NRf>  
Calibration Example  
A sample calibration program is given at the end of this appendix. If your system is Agilent BASIC, you can use the  
program with very little modification. Otherwise, use it as a guide for writing your own program.  
Calibration Language Dictionary  
The calibration commands are listed in alphabetical order. The format for each command follows that shown in "Chapter 3 -  
Language Dictionary" of the Programming Guide. Calibration error messages that can occur during GPIB calibration are  
shown within this guide (Table A-3 in Appendix A - Calibration).  
CAL:CURR  
This command is used to calibrate the output current. The command enters current value that you obtain from an external  
meter. (If you are entering the current value, allow time for the DVM to stabilize.) You must first select a calibration level  
(CAL:CURR:LEV) for the value being entered. Two successive values (one for each end of the calibration range) must be  
selected and entered. The power supply then computes new current calibration constants. These constants are not stored in  
nonvolatile memory until saved with the CAL:SAVE command.  
Command Syntax CALibrate:CURRent[:DATA] <NRf>  
Parameters (See applicable Output Ratings specification in "Chapter 1- General Information")  
Default Suffix  
A
Examples CAL: CURR 32 . 33 A CAL: CURR: DATA 5 . 00  
Query Syntax (None)  
Related Commands CAL:SAVE CAL:STAT  
CAL:CURR:LEV  
This command sets the power supply to a calibration point that is then entered with CAL:CURR[:DATA]. During  
calibration, two points must be entered and the low-end point (MIN) must be selected and entered first.  
Command Syntax CALibrate:CURRent:LEVel {MIN|MAX}  
Parameters {<CRD>|MINimum|MAXimum}  
Examples CAL: CURR: LEV MIN CAL: CURR: LEV MAX  
Query Syntax (None)  
Related Commands CAL:CURR[:DATA] CAL:STAT  
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CAL:CURR:MON (Series 668xA only)  
This command sets the power supply to the current monitor (IMON) calibration point that is then entered with  
CAL:CURR[:DATA]. The output current must be calibrated after CAL:CURR:MON is performed.  
Command Syntax CALibrate:CURRent:MONitor  
Parameters <NRf+>  
Examples CAL: CURR: MON CALibrate: CURRent: MONitor  
Query Syntax (None)  
Related Commands CAL:CURR[:DATA] CAL:STAT  
CAL:PASS  
This command enters a new calibration password. The command is active only when the power supply is already in the  
calibration mode. Unless it is changed subsequently to shipment, the password is the power supply’s four-digit model  
number. If the password is set to 0, password protection is removed and CAL:STAT ON is unrestricted. A new password is  
automatically stored in nonvolatile memory and does not have to be stored with the CAL:SAVE command.  
Command Syntax CALibrate:PASScode <NRf>  
Parameters <NRf>  
Examples CAL:PASS 6671  
Query Syntax (None)  
CAL:PASS 09.1993  
Related Commands CAL:STAT  
CAL:SAVE  
This command saves any new calibration constants (after a current or voltage calibration procedure has been completed) in  
nonvolatile memory.  
Command Syntax: CALibrate:SAVE  
Parameters (None)  
Examples CAL: SAVE  
Query Syntax (None)  
Related Commands CAL:CURR CAL:VOLT CAL:STAT  
CAL:STAT  
This command enables and disables the calibration mode. The calibration mode must be enabled before the power supply  
will accept any other calibration commands. The first parameter specifies the enabled or disabled state. The second  
parameter is the password. It is required if the calibration mode is being enabled and the existing password is not 0. If the  
second parameter is not entered or is incorrect, an error is generated and the calibration mode remains disabled. The query  
statement returns only the state, not the password.  
Whenever the calibration mode is changed from enabled to disabled, any new calibration constants are lost unless they have  
been stored with CAL:SAVE.  
Command Syntax: CALibrate:STATe <bool> [,<NRf>]  
Parameters {0 | OFF} | {1 | ON} [,<NRf>]  
*RST Value OFF  
Examples CAL:STAT 1,6671 CAL:STAT OFF  
Query Syntax CALibrate:STATe?  
Returned Parameters {0 | 1 }  
Related Commands CAL:PASS CAL:SAVE  
Calibration 99  
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CAL:VOLT  
This command is used to calibrate the output voltage. The command enters voltage value that you obtain from an external  
meter. (If you are entering the voltage value, allow time for the DVM to stabilize.) You must first select a calibration level  
(CAL:VOLT:LEV) for the value being entered. Two successive values (one for each end of the calibration range) must be  
selected and entered. The power supply then computes new voltage calibration constants. These constants are not stored in  
nonvolatile memory until saved with the CAL:SAVE command.  
Command Syntax CALibrate:VOLTage[:DATA] <NRf>  
Parameters (See applicable Output Ratings in "Chapter 1- General Information")  
Default Suffix  
A
Examples CAL: VOLT 322 . 5 MV CAL: VOLT: DATA 3 . 225  
Query Syntax (None)  
Related Commands CAL:SAVE CAL:STAT  
CAL:VOLT:LEV  
This command sets the power supply to a calibration point that is then entered with CAL:VOLT[:DATA]. During  
calibration, two points must be entered and the low-end point (MIN) must be selected and entered first.  
Command Syntax CALibrate:VOLTage:DATA {MIN|MAX}  
Parameters { < CRD > | MINimum | MAXimum}  
Examples CAL: VOLT: LEV MIN  
Query Syntax (None)  
CAL: VOLT: LEV MAX  
Related Commands CAL:VOLT[:DATA]  
CAL:STAT  
CAL:VOLT:PROT  
This command calibrates the power supply overvoltage protection (OV) circuit. The output voltage must be in calibration  
before this procedure is performed. Also, the power supply output must be enabled and operating in the constant voltage  
(CV) mode. If present, the optional relay accessory must either be disconnected or set to the off (open) state. The power  
supply automatically performs the calibration and stores the new OV constant in nonvolatile memory. CAL:VOLT:PROT  
is a sequential command that takes several seconds to complete.  
Command Syntax: CALibrate:VOLTage:PROTection  
Parameters (None)  
Example CAL: VOLT: PROT  
Query Syntax (None)  
Related Commands CAL:STAT  
Agilent BASIC Calibration Program  
The following program can be run on any controller operating under Agilent BASIC. The assumed power supply address is  
5 and calibration password is 6680. If required, change these parameters in the appropriate statements.  
Note  
If you are calibrating models 664x, 665x, or 667x, delete or comment out lines 640 through 670 in the  
following calibration program. These program lines are only required when calibrating models 668x.  
100 Calibration  
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10  
20  
30  
40  
! Agilent BASIC Calibration Program  
!
DIM Resp$ [255],Err_msg$[255]  
!
50 Volt_cal: !  
Voltage DAC calibration  
60  
Err_found=0  
70  
PRINT TABXY(5,10),"CONNECT INSTRUMENTS AS SHOWN IN FIG. A -1(1). Then Press Continue"  
80  
PAUSE  
90  
CLEAR SCREEN  
100  
110  
120  
130  
140  
150  
160  
170  
180  
190  
200  
210  
220  
230  
240  
250  
260  
270  
280  
290  
300  
310  
320  
330  
340  
350  
360  
370  
380  
390  
400  
410  
420  
430  
440  
450  
460  
470  
!
! Assign power supply GPIB address  
!
ASSIGN @Ps TO 705  
!
! Initialize power supply  
!
OUTPUT @Ps;"*RST;OUTPUT ON"  
!
! Password is optional - only required if set to non-zero value  
! Default password is the four-digit model number  
!
! LINE 240 PASSWORD MUST BE EDITED FOR MODEL OTHER THAN 6680  
!
OUTPUT @Ps;"CAL:STATE ON, 6680"  
1
OUTPUT @Ps;"CAL:VOLTAGE:LEVEL MIN"  
INPUT "ENTER VOLTAGE MEASUREMENT FROM EXTERNAL VOLTMETER",Volt_read  
OUTPUT @Ps;"CAL:VOLTAGE ";Volt_read  
OUTPUT @Ps;"CAL:VOLTAGE:LEVEL MAX"  
INPUT "ENTER VOLTAGE MEASUREMENT FROM EXTERNAL VOLTMETER",Volt_read  
OUTPUT @Ps;"CAL:VOLTAGE ";Volt_read  
!
! Calibrate overvoltage protection circuit  
!
OUTPUT @Ps;"CAL:VOLTAGE:PROTECTION"  
!
GOSUB Save_cal  
IF Err_found THEN  
INPUT "ERRORS have occurred, REPEAT VOLTAGE CALIBRATION ( Y 0R N )?",Resp$  
IF TRIM$(UPC$(Resp$[1,1] ) )="Y" THEN GOTO Volt_cal  
END IF  
IF Err_found THEN  
PRINT "VOLTAGE CALIBRATION NOT SAVED"  
ELSE  
PRINT "VOLTAGE CALIBRATION COMPLETE"  
END IF  
!
480 Current_cal: !  
Imon DAC and Current DAC calibration  
490  
500  
510  
520  
Err_found=0  
PRINT TABXY(5,10),"CONNECT INSTRUMENTS AS SHOWN IN FIG. A -1(2). Then Press Continue"  
PAUSE  
CLEAR SCREEN  
Figure A-2. Agilent BASIC Calibration Program  
Calibration 101  
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540  
550  
560  
570  
580  
590  
600  
610  
620  
630  
Password is optional - only required if set to non-zero value  
Default password is four-digit model number  
!
! LINE 590 PASSWORD MUST BE EDITED FOR MODEL OTHER THAN 6680  
!
OUTPUT @Ps;"CAL:STATE ON, 6680"  
OUTPUT @Ps;"VOLT:LEV 2"  
! Refer to Table A-1 for correct shunt value for model being calibrated  
!
INPUT "ENTER VALUE 0F CURRENT SHUNT BEING USED",Shunt_val  
STEPS 640 THROUGH 670 NOT USED ON 664x, 665x and 667x  
OUTPUT @Ps;"CAL:CURRENT:MONITOR"  
INPUT "ENTER VOLTAGE MEASUREMENT FROM EXTERNAL VOLTMETER",Volt_read  
Current=Volt_read/Shunt_val  
OUTPUT @Ps;"CAL:CURRENT ";Current  
OUTPUT @Ps;"CAL:CURRENT:LEVEL MIN"  
INPUT "ENTER VOLTAGE MEASUREMENT FROM EXTERNAL VOLTMETER",Volt_read  
Current=Volt_read/Shunt_val  
OUTPUT @Ps;"CAL:CURRENT ";Current  
OUTPUT @Ps;"CAL:CURRENT:LEVEL MAX"  
INPUT "ENTER VOLTAGE MEASUREMENT FROM EXTERNAL VOLTMETER",Volt_read  
Current=Volt_read/Shunt_val  
OUTPUT @Ps;"CAL:CURRENT ";Current  
GOSUB Save_cal  
640  
650  
660  
670  
680  
690  
700  
710  
720  
730  
740  
750  
760  
770  
780  
790  
800  
810  
820  
830  
840  
850  
860  
IF Err_found THEN  
INPUT "ERRORS have occurred, REPEAT CURRENT CALIBRATION ( Y 0R N )?",Resp$  
IF TRIM$(UPC$(Resp$[l,1] ))="Y" THEN GOTO Volt_cal  
END IF  
IF Err_found THEN  
PRINT "CURRENT CALIBRATION NOT SAVED"  
ELSE  
PRINT "CURRENT CALIBRATION COMPLETE"  
END IF  
STOP  
870 Save_cal: ! SAVE CALIBRATION  
880  
890  
900  
910  
920  
930  
940  
950  
960  
970  
980  
990  
1000  
1010  
1020  
1030  
1040  
REPEAT  
OUTPUT @Ps;"SYSTEM:ERROR?"  
ENTER @Ps;Err_num,Err_msg$  
IF Err_num< >0 THEN  
PRINT "ERROR: ";Err_msg$  
Err_found=1  
END IF  
UNTIL Err_num=0  
IF NOT Err_found THEN  
INPUT "SAVE CALIBRATION CONSTANTS ( Y 0R N )?",Resp$  
IF TRIM$(UPC$(Resp$[l,1] ))="Y" THEN  
OUTPUT @Ps;"CAL:SAVE"  
END IF  
END IF  
OUTPUT @Ps;"CAL:STATE OFF"  
RETURN  
END  
Figure A-2. Agilent BASIC Calibration Program (continued)  
102 Calibration  
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B
Operation Verification  
Introduction  
This appendix provides operation verification test procedures. The tests do not check all the operating parameters, but  
verify that the power supply is performing properly. The required test equipment and acceptable test results are specified in  
tables at the end of this appendix.  
Note  
Performance Tests, which check all the specifications of the power supply, are given in the applicable  
power supply Service Manual.  
Test Equipment Required  
List of Equipment  
The following equipment is required to perform the tests:  
Table B-1. Equipment Required for Verification Tests  
Equipment  
Characteristics  
Recommended Model  
Digital Voltmeter  
Resolution: 10 nV @ 1 V  
Readout: 8 1/2 digits  
Accuracy: 20 ppm  
Agilent 3458A  
Current Monitor Resistor  
Agilent 6641A, 51A, 52A  
Agilent 6642A, 43A, 44A, 45A, 53A, 54A, 55A  
Agilent 6671A  
Guildline 9230/100  
Guildline 9230/15  
Guildline 9230/300  
Guildline 9230/100  
Burster 1280S  
100 A, 0.01 Ω, 0.04%, 100 W  
15 A, 0.1 Ω, 0.04%, 25 W  
300 A, 0.001 Ω, 0.04%, 100 W  
l00 A, 0.001 Ω, 0.04%, 100 W  
1000 A, 0.1 mΩ, 0.05%  
Agilent 6672A, 73A, 74A, 75A  
Agilent 6680A, 81A  
Agilent 6682A, 83A, 84A  
Guildline 9230/300  
300 A, 0.1 mΩ, 0.05%  
Current Monitoring Resistor  
The 4-terminal current-monitoring resistor listed in Table B-1 is required to eliminate output current measurement error  
caused by voltage drops in leads and connections. The specified resistors have special current-monitoring terminals inside  
the load connection terminals. Connect the current monitor directly to these current-monitoring terminals.  
Operation Verification 103  
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Figure B-1. Verification Test Setup  
104 Operation Verification  
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Performing The Tests  
General Measurement Techniques  
Figure B-1 shows the setup for the tests. Be certain to use load leads of sufficient wire gauge to carry the output current (see  
Table 4-1). To avoid noise pickup, use coaxial cable or shielded pairs for the test leads.  
Programming the Power Supply  
Table 1-lb, Table 1-2b, Table 1-3b and Table 1-4b in Chapter 1 list the programming voltage and current ranges for each  
model. Enter the appropriate values from the front panel. The programming procedures assume you know how to operate  
the power supply from the front panel (see "Chapter 5 - Front Panel Operation").  
Order of Tests  
Perform the following tests for operation verification. Test 1 must be done first, followed by Tests 2 and 3 in any order.  
1 Turn-on Checkout  
2 Voltage Programming and Readback Accuracy  
3 Current Programming and Readback Accuracy  
Turn-on Checkout  
Perform the Turn-on Checkout as directed in "Chapter 3 - Turn-on Checkout".  
Note  
The power supply must pass turn-on selftest before you can proceed with these tests.  
Voltage Programming and Readback Accuracy  
This test verifies that the voltage programming, GPIB readback, and front panel display functions are within specifications.  
Figure B-1 shows the setup for the tests. Measure the dc output voltage directly at the sense connections of the output  
terminals or bus bars. Connect the output as shown.  
Table B-2. Voltage Programming and Readback Accuracy Tests  
Action  
Normal Result  
1
2
3
Turn off the power supply and connect a DVM across the  
sense terminals (see Figure B-1(1)).  
Turn on the power supply with no load and program the  
output for 0 volts and maximum programmable current.  
CV annunciator on. Output current near 0.  
Record voltage readings at DVM and on front panel  
display. (Subtract or add the specified readback limit to  
the actual output values).  
Readings within Low Voltage limits (see applicable test  
table).  
4
5
Program voltage to full scale.  
Record voltage readings of DVM and on front panel  
display. (Subtract or add the specified readback limit to  
the actual output values)  
Readings within High Voltage limits (see applicable test  
table).  
Operation Verification 105  
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Current Programming and Readback Accuracy  
This test verifies that the current programming and readback are within specification. Connect the appropriate current  
monitoring resistor (see Table B-1) as shown in Figure B-1(2). The accuracy of the resistor must be as specified in the table.  
Table B-3. Current Programming and Readback Accuracy Test  
Action  
Normal Result  
1
Turn off the power supply and connect the current monitoring  
resistor as shown in Figure B-1(2). Be certain to use wire of  
sufficient size to carry the maximum rated current of the  
supply (see Table 4-1 in Chapter 4).  
2
3
Connect a DVM across the resistor.  
Turn on the power supply and program the output for 5 volts  
and 0 amperes.  
4
Disable the output (  
)
WARNING  
ENERGY HAZARD for Series 668xA. The power supply can provide more than 240 VA at more than 2 V. If the  
output connections touch, severe arcing may occur resulting in burns, ignition or welding of parts. Do not attempt to  
make connections to live output circuits.  
5
6
Enable the output  
or OUTP ON).  
Observe the DVM voltage reading. Divide this by the  
resistance of the current monitor resistor. Record the result as  
the Low Current value in applicable test table.  
Value within Low Current limits (see applicable test  
table).  
7
Record the front panel display readback  
Value within specified readback limits (see  
applicable test table).  
8
9
Program output current to full scale.  
Repeat Steps 6 and 7.  
Both current readings within specified High Current  
and readback limits (see applicable test table).  
10  
Disable the output (  
).  
11 Remove the short from across the load.  
106 Operation Verification  
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Table B-4. Operation Verification Test Parameters for Series 664xA  
Test Description  
Minimum Spec  
Results *  
Maximum  
Spec  
Measurement  
Uncertainty  
MODEL Agilent 6641A  
Voltage Programming and Readback  
Low Voltage (0 V) Vout  
Front Panel Display Readback  
High Voltage (8 V) Vout  
-5 mV  
Vout -6.0 mV  
7.990 V  
Vout -11.6 mV  
Current Programming and Readback  
____________ mV  
____________ mV  
_____________V  
____________ mV  
+ 5 mV  
Vout +6.0 mV  
8.010 V  
2.0 µV  
2.0 µV  
88 µV  
88 µV  
Front Panel Display Readback  
Vout +11.6 mV  
Low Current (0 A) Iout  
Front Panel Display Readback  
High Current (20 A) Iout  
-26 mA  
Iout -18 mA  
19.944 A  
____________ mA  
____________ mA  
____________ A  
____________ mA  
+26 mA  
Iout +18 mA  
+20.056 A  
153 µA  
153 µA  
2.7 mA  
2.7 mA  
Front Panel Display Readback  
Iout -48 mA  
Iout +48 mA  
MODEL Agilent 6642A  
Voltage Programming and Readback  
Low Voltage (0 V) Vout  
-10 mV  
Vout -15 mV  
19.978 V  
Vout -29 mV  
Current Programming and Readback  
____________ mV  
____________ mV  
_____________V  
____________ mV  
+ 10 mV  
Vout +15 mV  
20.022 V  
2.0 µV  
2.0 µV  
335 µV  
335 µV  
Front Panel Display Readback  
High Voltage (20 V) Vout  
Front Panel Display Readback  
Vout +29 mV  
Low Current (0 A) Iout  
Front Panel Display Readback  
High Current (10 A) Iout  
-13 mA  
Iout -9.1 mA  
9.972 A  
____________ mA  
____________ mA  
____________ A  
____________ mA  
+13 mA  
Iout +9.1 mA  
+10.028 A  
20 µA  
20 µA  
3.1 mA  
3.1 mA  
Front Panel Display Readback  
Iout -24.1 mA  
Iout +24.1 mA  
MODEL Agilent 6643A  
Voltage Programming and Readback  
Low Voltage (0 V) Vout  
-15 mV  
Vout -25 mV  
34.964 V  
Vout -50 mV  
Current Programming and Readback  
____________ mV  
____________ mV  
_____________V  
____________ mV  
+ 15 mV  
Vout +25 mV  
35.036 V  
2.0 µV  
2.0 µV  
525 µV  
525 µV  
Front Panel Display Readback  
High Voltage ( 35 V) Vout  
Front Panel Display Readback  
Vout +50 mV  
Low Current (0 A) Iout  
Front Panel Display Readback  
High Current ( 6 A) Iout  
-6.7 mA  
Iout -5 mA  
5.985 A  
____________ mA  
____________ mA  
____________ A  
____________ mA  
+6.7 mA  
Iout +5 mA  
6.015 A  
16 µA  
16 µA  
1.1 mA  
1.1 mA  
Front Panel Display Readback  
Iout -14 mA  
Iout +14 mA  
MODEL Agilent 6644A  
Voltage Programming and Readback  
Low Voltage (0 V) Vout  
-26 mV  
Vout -40 mV  
59.938 V  
Vout -82 mV  
Current Programming and Readback  
____________ mV  
____________ mV  
_____________V  
____________ mV  
+ 26 mV  
Vout +40 mV  
60.062 V  
2.0 µV  
2.0 µV  
845 µV  
845 µV  
Front Panel Display Readback  
High Voltage ( 60 V) Vout  
Front Panel Display Readback  
Vout +82 mV  
Low Current (0 A) Iout  
-4.1 mA  
Iout -3 mA  
3.491 A  
____________ mA  
____________ mA  
____________ A  
____________ mA  
+4.1 mA  
Iout +3 mA  
+3.509 A  
16 µA  
16 µA  
500 µA  
500 µA  
Front Panel Display Readback  
High Current (3.5 A) Iout  
Front Panel Display Readback  
Iout -8.3 mA  
Iout +8.3 mA  
* Enter your test results in this column.  
Operation Verification 107  
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Table B-4. Operation Verification Test Parameters for Series 664xA (continued)  
Test Description  
Minimum Spec  
Results *  
Maximum  
Spec  
Measurement  
Uncertainty  
MODEL Agilent 6645A  
Voltage Programming and Readback  
Low Voltage (0 V) Vout  
-51 mV  
Vout -80 mV  
119.877 V  
____________ mV  
____________ mV  
_____________V  
____________ mV  
+ 51 mV  
Vout +80 mV  
120.123 V  
2.0 µV  
2.0 µV  
1.7 mV  
1.7 mV  
Front Panel Display Readback  
High Voltage (120 V) Vout  
Front Panel Display Readback  
Vout -164 mV  
Vout +164 mV  
Current Programming and Readback  
Low Current (0 A) Iout  
-1.7 mA  
Iout -1.3 mA  
1.496 A  
____________ mA  
____________ mA  
____________ A  
____________ mA  
+1.7 mA  
Iout +1.3 mA  
+1.504 A  
16 µA  
16 µA  
188 µA  
188 µA  
Front Panel Display Readback  
High Current (1.5 A) Iout  
Front Panel Display Readback  
Iout -3.5 mA  
Iout +3.5 mA  
* Enter your test results in this column.  
108 Operation Verification  
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Table B-5. Operation Verification Test Parameters for Series 665xA  
Test Description  
Minimum Spec  
Results *  
Maximum  
Spec  
Measurement  
Uncertainty  
MODEL Agilent 6651A  
Voltage Programming and Readback  
Low Voltage (0 V) Vout  
Front Panel Display Readback  
High Voltage (8 V) Vout  
-5 mV  
Vout -6.0 mV  
7.990 V  
Vout -11.6 mV  
Current Programming and Readback  
____________ mV  
____________ mV  
_____________V  
____________ mV  
+ 5 mV  
Vout +6.0 mV  
8.010 V  
2.0 µV  
2.0 µV  
88 µV  
88 µV  
Front Panel Display Readback  
Vout +11.6 mV  
Low Current (0 A) Iout  
Front Panel Display Readback  
High Current (50 A) Iout  
-60 mA  
Iout -67 mA  
49.865 A  
____________ mA  
____________ mA  
____________ A  
____________ mA  
+60 mA  
Iout +67 mA  
+50.135 A  
150 µA  
150 µA  
10.7 mA  
10.7 mA  
Front Panel Display Readback  
Iout -142 mA  
Iout +142 mA  
MODEL Agilent 6652A  
Voltage Programming and Readback  
Low Voltage (0 V) Vout  
-10 mV  
Vout -15 mV  
19.978 V  
Vout -29 mV  
Current Programming and Readback  
____________ mV  
____________ mV  
_____________V  
____________ mV  
+ 10 mV  
Vout +15 mV  
20.022 V  
2.0 µV  
2.0 µV  
335 µV  
335 µV  
Front Panel Display Readback  
High Voltage (20 V) Vout  
Front Panel Display Readback  
Vout +29 mV  
Low Current (0 A) Iout  
Front Panel Display Readback  
High Current (25 A) Iout  
-25 mA  
Iout -26 mA  
24.937 A  
____________ mA  
____________ mA  
____________ A  
____________ mA  
+25 mA  
Iout +26 mA  
+25.063 A  
153 µA  
153 µA  
3.5 mA  
3.5 mA  
Front Panel Display Readback  
Iout -63.5 mA  
Iout +63.5 mA  
MODEL Agilent 6653A  
Voltage Programming and Readback  
Low Voltage (0 V) Vout  
-15 mV  
Vout -25 mV  
34.964 V  
Vout -50 mV  
Current Programming and Readback  
____________ mV  
____________ mV  
_____________V  
____________ mV  
+ 15 mV  
Vout +25 mV  
35.036 V  
2.0 µV  
2.0 µV  
525 µV  
525 µV  
Front Panel Display Readback  
High Voltage ( 35 V) Vout  
Front Panel Display Readback  
Vout +50 mV  
Low Current (0 A) Iout  
-13 mA  
Iout -15 mA  
14.964 A  
____________ mA  
____________ mA  
____________ A  
____________ mA  
+13 mA  
Iout +15 mA  
15.036 A  
17 µA  
17 µA  
6.2 mA  
6.2 mA  
Front Panel Display Readback  
High Current ( 15 A) Iout  
Front Panel Display Readback  
Iout -37.5 mA  
Iout +37.5 mA  
MODEL Agilent 6654A  
Voltage Programming and Readback  
Low Voltage (0 V) Vout  
-26 mV  
Vout -40 mV  
59.938 V  
Vout -82 mV  
Current Programming and Readback  
____________ mV  
____________ mV  
_____________V  
____________ mV  
+ 25 mV  
Vout +40 mV  
60.062 V  
2.0 µV  
2.0 µV  
845 µV  
845 µV  
Front Panel Display Readback  
High Voltage ( 60 V) Vout  
Front Panel Display Readback  
Vout +82 mV  
Low Current (0 A) Iout  
Front Panel Display Readback  
High Current (9 A) Iout  
-8 mA  
Iout -7 mA  
8.978 A  
____________ mA  
____________ mA  
____________ A  
____________ mA  
+8 mA  
Iout +7 mA  
+9.022 A  
16 µA  
16 µA  
2.5 mA  
2.5 mA  
Front Panel Display Readback  
Iout -20.5 mA  
Iout +20.5 mA  
* Enter your test results in this column.  
Operation Verification 109  
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Table B-5. Operation Verification Test Parameters for Series 665xA (continued)  
Test Description  
Minimum Spec  
Results *  
Maximum  
Spec  
Measurement  
Uncertainty  
MODEL Agilent 6655A  
Voltage Programming and Readback  
Low Voltage (0 V) Vout  
-51 mV  
Vout -80 mV  
119.877 V  
____________ mV  
____________ mV  
_____________V  
____________ mV  
+ 51 mV  
Vout +80 mV  
120.123 V  
2.0 µV  
2.0 µV  
1.7 mV  
1.7 mV  
Front Panel Display Readback  
High Voltage (120 V) Vout  
Front Panel Display Readback  
Vout -164 mV  
Vout +164 mV  
Current Programming and Readback  
Low Current (0 A) Iout  
Front Panel Display Readback  
High Current (4 A) Iout  
-4 mA  
Iout -3 mA  
3.990A  
____________ mA  
____________ mA  
____________ A  
____________ mA  
+4 mA  
Iout +3 mA  
+4.010 A  
15 µA  
15 µA  
586 µA  
586 µA  
Front Panel Display Readback  
Iout -9 mA  
Iout +9 mA  
* Enter your test results in this column.  
110 Operation Verification  
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Table B-6. Operation Verification Test Parameters for Series 667xA  
Test Description  
Minimum Spec  
Results *  
Maximum  
Spec  
Measurement  
Uncertainty  
MODEL Agilent 6671A  
Voltage Programming and Readback  
Low Voltage (0 V) Vout  
Front Panel Display Readback  
High Voltage (8 V) Vout  
-8 mV  
Vout -12 mV  
7.9888 V  
Vout -16 mV  
Current Programming and Readback  
____________ mV  
____________ mV  
_____________V  
____________ mV  
+ 8 mV  
Vout +12 mV  
8.0012 V  
1.6 µV  
1.6 µV  
100 µV  
100 µV  
Front Panel Display Readback  
Vout +16 mV  
Low Current (0 A) Iout  
-125 mA  
Iout -150 mA  
219.655 A  
____________ mA  
____________ mA  
____________ A  
____________ mA  
+125 mA  
Iout +150 mA  
220.345 A  
50 µA  
50 µA  
92 mA  
92 mA  
Front Panel Display Readback  
High Current (220 A) Iout  
Front Panel Display Readback  
Iout -370 mA  
Iout +370 mA  
MODEL Agilent 6672A  
Voltage Programming and Readback  
Low Voltage (0 V) Vout  
-20 mV  
Vout -30 mV  
19.972 V  
Vout -40 mV  
Current Programming and Readback  
____________ mV  
____________ mV  
_____________V  
____________ mV  
+ 20 mV  
Vout +30 mV  
20.028 V  
2.0 µV  
2.0 µV  
335 µV  
335 µV  
Front Panel Display Readback  
High Voltage (20 V) Vout  
Front Panel Display Readback  
Vout +40 mV  
Low Current (0 A) Iout  
-60 mA  
Iout -100 mA  
99.84 A  
____________ mA  
____________ mA  
____________ A  
____________ mA  
+60 mA  
Iout +100 mA  
+100.16 A  
40 µA  
40 µA  
41 mA  
41 mA  
Front Panel Display Readback  
High Current (100 A) Iout  
Front Panel Display Readback  
Iout -200 mA  
Iout +200 mA  
MODEL Agilent 6673A  
Voltage Programming and Readback  
Low Voltage (0 V) Vout  
-35 mV  
Vout -50 mV  
34.951 V  
Vout -68 mV  
Current Programming and Readback  
____________ mV  
____________ mV  
_____________V  
____________ mV  
+ 35 mV  
Vout +50 mV  
35.049 V  
2.0 µV  
2.0 µV  
526 µV  
526 µV  
Front Panel Display Readback  
High Voltage ( 35 V) Vout  
Front Panel Display Readback  
Vout +68 mV  
Low Current (0 A) Iout  
-40 mA  
Iout -60 mA  
59.9 A  
____________ mA  
____________ mA  
____________ A  
____________ mA  
+40 mA  
Iout +60 mA  
60.1 A  
31 µA  
31 µA  
25 mA  
25 mA  
Front Panel Display Readback  
High Current ( 60 A) Iout  
Front Panel Display Readback  
Iout -120 mA  
Iout +120 mA  
MODEL Agilent 6674A  
Voltage Programming and Readback  
Low Voltage (0 V) Vout  
-60 mV  
Vout -90 mV  
59.916 V  
____________ mV  
____________ mV  
_____________V  
____________ mV  
+ 60 mV  
Vout +90 mV  
60.084 V  
2.2 µV  
2.2 µV  
1 mV  
Front Panel Display Readback  
High Voltage ( 60 V) Vout  
Front Panel Display Readback  
Vout -132 mV  
Vout +132 mV  
1 mV  
Current Programming and Readback  
Low Current (0 A) Iout  
Front Panel Display Readback  
High Current (35 A) Iout  
-25 mA  
Iout -35 mA  
34.94 A  
____________ mA  
____________ mA  
____________ A  
____________ mA  
+25 mA  
Iout +35 mA  
35.06 A  
21 µA  
21 µA  
15 mA  
15 mA  
Front Panel Display Readback  
Iout -70 mA  
Iout +70 mA  
* Enter your test results in this column.  
Operation Verification 111  
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Table B-6. Operation Verification Test Parameters for Series 667xA (continued)  
Test Description  
Minimum Spec  
Results *  
Maximum  
Spec  
Measurement  
Uncertainty  
MODEL Agilent 6675A  
Voltage Programming and Readback  
Low Voltage (0 V) Vout  
-120 mV  
Vout -180 mV  
119.832 V  
____________ mV  
____________ mV  
_____________V  
____________ mV  
+ 120 mV  
Vout +180 mV  
120.168 V  
3.0 µV  
3.0 µV  
1.7 mV  
1.7 mV  
Front Panel Display Readback  
High Voltage (120 V) Vout  
Front Panel Display Readback  
Vout -240 mV  
Vout +240 mV  
Current Programming and Readback  
Low Current (0 A) Iout  
Front Panel Display Readback  
High Current (18 A) Iout  
-12 mA  
Iout -18 mA  
17.97 A  
____________ mA  
____________ mA  
____________ A  
____________ mA  
+12 mA  
Iout +18 mA  
+18.03 A  
20 µA  
20 µA  
7.5 mA  
7.5 mA  
Front Panel Display Readback  
Iout -36 mA  
Iout +36 mA  
* Enter your test results in this column.  
112 Operation Verification  
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Table B-7. Operation Verification Test Parameters for Series 668xA  
Test Description  
Minimum Spec  
Results *  
Maximum  
Spec  
Measurement  
Uncertainty  
MODEL Agilent 6680A  
Voltage Programming and Readback  
Low Voltage (0 V) Vout  
Front Panel Display Readback  
High Voltage (5 V) Vout  
-0.005 V  
Vout -7.5 mV  
4.9943 V  
Vout -10 mV  
Current Programming and Readback  
____________ V  
____________ mV  
_____________V  
____________ mV  
+ 0.005 V  
Vout +7.5 mV  
5.0057 V  
1.0 µV  
1.0 µV  
56 µV  
56 µV  
Front Panel Display Readback  
Vout +10 V  
Low Current (0 A) Iout  
-0.450 A  
Iout -600 mA  
873.675 A  
____________ A  
____________ mA  
____________ A  
____________ A  
+0.450 A  
15 mA  
15 mA  
461 mA  
461 mA  
Front Panel Display Readback  
High Current (875 A) Iout  
Front Panel Display Readback  
Iout +600 mA  
+876.325 A  
Iout +1.475 A  
Iout -1.475 A  
MODEL Agilent 6681A  
Voltage Programming and Readback  
Low Voltage (0 V) Vout  
Front Panel Display Readback  
High Voltage (8 V) Vout  
-0.008 V  
Vout -12 mV  
7.9888 V  
Vout -16 mV  
Current Programming and Readback  
____________ V  
____________ mV  
_____________V  
____________ mV  
+ 0.008 V  
Vout +12 mV  
8.0112 V  
1.0 µV  
1.0 µV  
88 µV  
88 µV  
Front Panel Display Readback  
Vout +16 mV  
Low Current (0 A) Iout  
-0.300 A  
Iout -400 mA  
579.12 A  
____________ A  
____________ mA  
____________ A  
____________ mA  
+0.300 A  
Iout +400 mA  
+580.88 A  
15 mA  
15 mA  
311 mA  
311 mA  
Front Panel Display Readback  
High Current (580 A) Iout  
Front Panel Display Readback  
Iout -980 mA  
Iout +980 mA  
MODEL Agilent 6682A  
Voltage Programming and Readback  
Low Voltage (0 V) Vout  
-21 mV  
Vout -32 mV  
20.970 V  
Vout -42 mV  
Current Programming and Readback  
____________ mV  
____________ mV  
_____________V  
____________ mV  
+ 21 mV  
Vout +32 mV  
348 µV  
1.7 µV  
1.7 µV  
Front Panel Display Readback  
High Voltage ( 21 V) Vout  
Front Panel Display Readback  
Vout +42 mV  
348 µV  
Low Current (0 A) Iout  
-125 mA  
Iout -165 mA  
239.635 A  
____________ mA  
____________ mA  
____________ A  
____________ mA  
+125 mA  
Iout +165 mA  
240.365 A  
1.5 mA  
1.5 mA  
83 mA  
83 mA  
Front Panel Display Readback  
High Current ( 240 A) Iout  
Front Panel Display Readback  
Iout -405 mA  
Iout +405 mA  
MODEL Agilent 6683A  
Voltage Programming and Readback  
Low Voltage (0 V) Vout  
-32 mV  
Vout -48 mV  
31.955 V  
Vout -?? mV  
Current Programming and Readback  
____________ mV  
____________ mV  
_____________V  
____________ mV  
+ 32 mV  
Vout +48 mV  
32.044 V  
1.9 µV  
1.9 µV  
488 µV  
488 µV  
Front Panel Display Readback  
High Voltage ( 32 V) Vout  
Front Panel Display Readback  
Vout +?? mV  
Low Current (0 A) Iout  
-85 mA  
Iout -60 mA  
159.755 A  
____________ mA  
____________ mA  
____________ A  
____________ mA  
+85 mA  
Iout +60 mA  
160.245 A  
1.5 µA  
1.5 µA  
35.6 mA  
35.6 mA  
Front Panel Display Readback  
High Current (160 A) Iout  
Front Panel Display Readback  
Iout -270 mA  
Iout +270 mA  
* Enter your test results in this column.  
Table B-7. Operation Verification Test Parameters for Series 668xA (continued)  
Operation Verification 113  
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Test Description  
Minimum Spec  
Results *  
Maximum  
Spec  
Measurement  
Uncertainty  
MODEL Agilent 6684A  
Voltage Programming and Readback  
Low Voltage (0 V) Vout  
-40 mV  
Vout -60 mV  
39.944 V  
Vout -80 mV  
Current Programming and Readback  
____________ mV  
____________ mV  
_____________V  
____________ mV  
+ 40 mV  
Vout +60 mV  
40.056 V  
2.0 µV  
2.0 µV  
590 µV  
590 µV  
Front Panel Display Readback  
High Voltage (40 V) Vout  
Front Panel Display Readback  
Vout +80 mV  
Low Current (0 A) Iout  
-65 mA  
Iout -90 mA  
127.807 A  
____________ mA  
____________ mA  
____________ A  
____________ mA  
+65 mA  
Iout +90 mA  
128.193 A  
1.5 mA  
1.5 mA  
24.1 mA  
24.1 mA  
Front Panel Display Readback  
High Current (128 A) Iout  
Front Panel Display Readback  
Iout -218 mA  
Iout +218 mA  
* Enter your test results in this column.  
114 Operation Verification  
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C
Line Voltage Conversion  
Series 664xA and 665xA Power Supplies  
SHOCK HAZARD. Hazardous voltage can remain inside the power supply even after it has been  
turned off. This procedure should only be done by qualified electronics service personnel.  
Line voltage conversion is accomplished by:  
■
■
Series 664xA - setting line voltage select switches.  
Series 665xA - changing wire and jumper positions on the ac input of the main power transformer.  
Proceed as follows:  
1. Turn off the ac power to the supply and disconnect the power cord from the power source.  
2. Remove the four screws that secure the two carrying straps and outer cover.  
3. Slightly spread the bottom rear of the cover and pull it back to disengage it from the front panel.  
4. Slide the dustcover back far enough to expose the select switches (see Figure C-1) or the line select jumpers (see Figure  
C-2).  
5. On the Series 664xA supply, move the line voltage select switches to the positions corresponding to the desired line  
voltage.  
6. On the Series 665xA supply, move the line voltage select jumpers to the positions corresponding to the desired line  
voltage. To disconnect it from the transformer tab, pull the wire straight up. Moving the wire from side-to-side can  
damage the tab.  
7. Replace the top cover and secure the carrying straps.  
8. Change the line fuse (on the rear panel) to the proper value for the new line voltage (see Table 1-6 in Chapter 1).  
Figure C-1. Series 664xA Line Select Switches  
Line Voltage Conversion 115  
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Figure C-2. Series 665xA Line Select Jumpers  
Series 667xA Power Supplies  
SHOCK HAZARD. Hazardous voltage can remain inside the power supply even after it has been  
turned off. This procedure should only be done by qualified electronics service personnel.  
Line voltage conversion is accomplished by setting a line voltage select switch. Proceed as follows:  
1. Turn off the ac power and disconnect the power cord from the power source.  
2. Remove the four screws securing the carrying straps and dustcover.  
3. Spread the bottom rear of the dustcover and pull it back to disengage it from the front panel.  
4. Slide the dustcover back far enough to expose the line select switch (see Figure C-3).  
5. Observe the input rail LED under the RFI shield. If the LED is on, there is still hazardous voltage inside the supply.  
Wait until the LED goes out (this may take several minutes) before proceeding.  
6. Connect a dc voltmeter across test points TP1 and TP2. (It may be necessary to remove the RFI shield in order to reach  
these test points. The shield is secured by four screws on each side.) When the voltmeter indicates 60 volts or less, it is  
safe to work inside the power supply.  
7. Locate the line selector switch and slide it to the desired position.  
8. If you removed it in step 6, be sure to replace the RFI shield.  
9. Replace the dustcover.  
Figure C-3. Series 667xA Line Select Switch  
116 Line Voltage Conversion  
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Series 668xA Power Supplies  
SHOCK HAZARD. Hazardous voltage can remain inside the power supply even after it has been  
turned off. This procedure should only be done by qualified electronics service personnel.  
Line voltage conversion is accomplished by changing jumper cable positions on the ac input of the main power transformer.  
Proceed as follows:  
1. Turn off the power switch and disconnect the power cord from the power source or turn off the power disconnect switch.  
2. Remove the four screws that secure the two carrying straps and outer cover.  
3. Slightly spread the bottom rear of the cover and pull it back to disengage it from the front panel.  
4. Remove the outer cover by sliding it back towards the rear of the supply.  
5. Observe the input rail LEDs under the inner cover (see Figure C-4). If the LEDs are on, there is still hazardous voltage  
inside the supply. Wait until they both go out (this may take several minutes) before proceeding. (If one LED remains on  
while the other goes out, the power supply probably has a defect that requires service.)  
If you cannot see the LEDs through the hole in the inner cover, then wait until power has been removed  
for at least 15 minutes before proceeding to the next step.  
6. Remove the screws securing the inner cover (see Figure C-4).  
7. Remove the inner cover.  
8. Locate the three line conversion cables (A,B,C in Figure C-5). All three cables will be connected to the jacks that  
correspond to one of the voltage ranges (1 or 2, Figure C-5).  
9. Unplug the cables from their present jacks and plug them into the jacks for the other range.  
10. Replace the inner cover.  
Note  
Be sure to replace all of the screws removed in Step 6. All the screws are not needed for mechanical  
security, but they are required to ensure proper magnetic shielding.  
11. Replace the outer cover.  
12. Remove the three fuses from the rear panel. If required, first remove the ac safety cover (see Figure 2-4).  
13. Replace the fuses with the proper ones for the new range (see Table 1-6 in Chapter 1).  
14. If required, replace the ac safety cover.  
Reconnect the power and turn on the power supply.  
Line Voltage Conversion 117  
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Figure C-4. Removing the Series 668xA Inner Cover  
Figure C-5. Series 668xA Line Conversion Jumpers  
118 Line Voltage Conversion  
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D
Digital Port Functions  
Digital Connector  
A 4-pin connector and a quick-disconnect mating plug are provided for digital input and output signals (see Figure D-l for  
wiring connections, and Table 1-5 in Chapter 1 for electrical characteristics). This digital port can be configured to provide  
either Fault/Inhibit or Digital I/O functions.  
Note  
Consistent with good engineering practice, twist and shield all signal wires to and from the digital  
connector.  
Figure D-1. Digital Port Connector  
Fault/Inhibit Operation  
As shipped from the factory, the digital port is configured to provide a fault indicator (FLT) output and a remote (INH)  
input. Unplug the mating plug to make the connections. After you have finished making all connections, plug the wired plug  
back into the connector.  
FLT Output  
(pins 1 and 2)  
Used to indicate that a fault has occurred in power supply. Pins 1 and 2 are the open collector  
output of an optocoupler, with pin 1 the collector and pin 2 the emitter. When a fault has occurred,  
pin 1 is driven low with respect to pin 2 (negative-true).  
INH Input (pin 3)  
Used to shut down the power supply output. Pin 3 is a high impedance input. The supply shuts  
down when this input is driven low (negative-true). This can be done by shorting pin 3 to pin 4.  
INH Common  
Provides the common connection for the INH input.  
(pin 4)  
Three examples are provided to show how to use the FLT/INH circuits of your power supply. Use twisted wire connections  
to reduce or prevent EM in all cases. If shielded wire is used, connect only one end of the shield to the chassis signal ground  
binding post to prevent ground loops.  
Digital Port Functions 119  
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In Figure D-2, the INH input is connected to a switch that shorts pin 3 to pin 4 whenever it is necessary to externally disable  
the output of the supply. This will activate the remote inhibit (RI) fault protection circuit, causing the front panel Prot  
annunciator to come on. It also sets the RI event bit in the supply’s Questionable Status Event register (see "Chapter 4-  
Status Reporting" in the Programming Guide). To re-enable the supply after it has been disabled by the INH input, first  
open the connection between pins 3 and 4. Then clear the protection circuit either from the front panel (see "Chapter 5 -  
Front Panel Operation" in this guide) or over the GPIB (see the Programming Guide).  
GPIB  
Figure D-2. Example of Inhibit Input  
In Figure D-3A, the FLT output is connected to a relay driver circuit that energizes a relay whenever a fault condition  
occurs in the power supply. The relay can be used to physically disconnect the output of the power supply from the load.  
The FLT output is generated by the logical ORing of the power supply’s Operation, Questionable, and Event status summary  
bits (see "Chapter 4 - Status Reporting” in the Programming Guide). You can cause one or more events to activate the FLT  
output by enabling the appropriate events in these status registers. The fault condition is cleared by first removing the cause  
of the fault and then reading the appropriate status event register(s).  
In Figure D-3B, the FLT output of one supply is connected to the INH input of another supply. Although only two supplies  
are shown, it is possible to chain other supplies with this arrangement. A fault condition in any one of the power supplies  
will disable all of them without intervention either by the controller or external circuitry. The controller can be made aware  
of the fault via a service request (SRQ) generated by the Questionable Status summary bit (see "Chapter 4 - Status  
Reporting" in the Programming Guide).  
Note  
The INH input cannot be used to disable outputs set from the external voltage programming port.  
120 Digital Port Functions  
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GPIB  
GPIB  
GPIB  
Figure D-3. Examples of FLT Outputs  
Figure D-4. Digital Port Configuration Jumper  
Digital Port Functions 121  
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Changing The Port Configuration  
As shipped from the factory, the digital port is configured for FLT/INH operation. You can change the configuration of the  
port to operate as a general-purpose digital input/output port to control your custom circuitry as shown in Figure D-4. To  
change the port configuration, you must move a jumper on the GPIB board.  
Shock Hazard. Hazardous voltage can remain inside the power supply even after it has been turned off.  
This procedure should only be done by qualified electronics service personnel.  
Proceed as follows:  
1. Turn off the power supply and disconnect the power cord from the power source or turn off the power disconnect switch  
(Series 668xA).  
2. Remove the four screws that secure the two carrying straps and outer cover.  
3. Spread the bottom rear of the cover and pull it back to disengage it from the front panel.  
4. Slide the outer cover back to expose the top of the GPIB board.  
5. Refer to Figure D-4 and use needle-nose pliers to move the jumper to the Digital I/O position.  
6. Replace the outer cover, and secure the carrying straps.  
7. Make the necessary wire connections to the digital connector.  
Digital I/O Operation  
The digital port can be configured (see Figure D-4) to provide a digital input/output to be used with custom digital interface  
circuits or relay circuits. Some examples are shown Figure D-5. See Figure D-1 for the pin assignments of the mating plug  
and Table 1-5 for the electrical characteristics of the port. See DIG:DATA[:VAL] in “Chapter 3 - Language Dictionary" of  
the Programming Guide for information on programming the port. The digital port pins are as follows:  
OUT 0 (pin 1)  
This port can only be used as an open-collector output. It is assigned a bit weight of 1.  
This port can only be used as an open-collector output. It is assigned a bit weight of 2.  
This port can be programmed to be either a high impedance input or an open-collector output.  
This pin is the common connection for the Digital I/O ports.  
OUT 1 (pin 2)  
IN/OUT 2 (pin 3)  
Common (pin 4)  
Figure D-5. Digital l/O Port Applications  
122 Digital Port Functions  
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Relay Link Operation  
The digital port can be configured to provide relay control outputs for the Agilent 59510A or 59511A Relay Accessory.  
Refer to Figure D-1 for the pin assignments of the mating plug.  
Not used with units that output more than 50 amps.  
RLY SEND  
(pin 1)  
Provides the serial data to control the relays in the Relay Accessory.  
(pin 2)  
(Not used)  
RLY RTN  
(pin 3)  
Receives the data readback that indicates the status of the relays in the Relay Accessory.  
Common  
Common connection for the RLY SEND and RLY RTN lines.  
(pin 4)  
Figure D-6 shows how to connect your power supply to an Agilent 59510A or 59511A Relay Accessory when the digital  
port is configured for relay link operation. An error will be generated if you attempt to program the relay box without first  
configuring the digital port for relay link operation. For more information about programming the relay, refer to  
OUTP:REL[:STAT] in Chapter 3 of the Programming Guide. For more information about the Relay Accessory, refer to its  
manual (see Table 1-6).  
Figure D-6. Relay Link Connections  
Digital Port Functions 123  
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E
Current Loop Compensation (Series 668xA Only)  
This section describes how you may use current loop compensation to optimize for inductive loads or for fast CV/CC mode  
crossover. A 7-position compensation switch for this purpose is located under the cover on the rear of the power supply.  
Function Of Loop Compensation  
Figure E-1 shows the switch settings for specific combinations of load inductance and resistance. Two sets of curves show  
the small-signal response for each model. The dashed curves represent programming performance of no more than 10%  
current overshoot. The solid curves represent operating conditions with 25% overshoot. The curve obtained with all  
switches open gives the fastest CC mode crossover response time. However, as shown by these curves, the loop will not  
tolerate larger inductances unless the load resistance is increased. The curve described when all switch positions are closed  
shows the as-shipped performance curve. This position provides 10% overshoot and fast CV/CC crossover performance for  
load inductances that are specific for each model. (For Models 6680A and 6681A, this curve ranges from 100 µohms at  
15 µhenries to about 100 milliohms at 40 millihenries.). You can select a different compensation curve by opening a  
specific switch or combination of switches.  
Table E-1 shows some specific L ÷ R ratios and the switch positions required for these ratios. Table E-1 is valid only for  
Models 6680A and 6681A - you must use the curves for the remaining models. The corresponding 10% overshoot  
curves are shown in Figure E-1. As operation moves along the curves from left to right, the switch positions must be  
changed as shown along the X-axis.  
Table E-1.  
Settings For CC Loop Compensation Switch (Models 6680A and 6681A Only)  
Load Characteristic (L/R)  
1Switch Setting  
7
0
1
0
1
0
1
0
1
0
1
0
1
0
1
6
0
1
0
1
0
1
0
1
0
1
0
1
1
0
5
0
1
0
1
0
1
0
1
0
1
1
0
0
0
4
0
1
0
1
0
1
0
1
1
0
0
0
0
0
3
0
1
0
1
0
1
1
0
0
0
0
0
0
0
2
0
1
0
1
1
0
0
0
0
0
0
0
0
0
1
0
1
1
0
0
0
0
0
0
0
0
0
0
0
1 µH/3 mΩ  
215 µH/100 µΩ  
30 µH/100 µΩ  
100 µH/100 µΩ  
150 µH/100 µΩ  
600 µH/100 µΩ  
1.2 mH/100 µΩ  
4 mH/100 µΩ  
10 mH/100 µΩ  
40 mH/100µΩ  
100 mH/100 µΩ  
380 mH/100 µΩ  
650 mH/100 µΩ  
7 H/100 µΩ  
1
"1" = switch closed; "0" = switch open. 2 Factory setting.  
For example, examine Figure E-l for the Model 6680A/6681A. The chart shows that a load comprised of about  
Current Loop Compensation (Series 668xA Only) 125  
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1 millihenry inductance and 100 micro ohms resistance (see point  
obtain 10% overshoot. If the load resistance is increased to 1 milliohm, then the operating position will be to the left of the  
existing compensation curve (see point ). This will result in a stable condition with less overshoot, but greater CV/CC  
) requires switch setting 9 (only switch 3 closed) to  
crossover time than if the curve defined by switch setting 8 were used. If the load resistance remains at 1 milliohm but the  
load inductance increases to 10 millihenries, then the operating position will be far to the right of the compensation curve  
(see point  
). This results in a less stable condition with more overshoot. To obtain better operation at point  
, use the  
compensation curve defined by switch setting 13 (Model 6680A) or 12 (Model 6681A).  
Most operating conditions will not fall directly on a curve and you will have to interpolate between curves. Generally,  
moving to the left of a given curve increases stability. However, at large values of inductance the curves become almost  
vertical because the load resistance has no effect on dampening the system. For Models 6680A and 6681A, the most stable  
points are on the solid curves shown in Figure E-l. Points to the right or left of a curve will have more overshoot. Note the  
two dashed vertical lines at switch setting 25 for Models 6682A, 6683A, and 6684A. Operation between these lines will  
result in somewhat increased stability.  
Note  
The best procedure is to test your settings under real operating conditions. For help in tailoring a specific  
CC compensation, contact your Agilent Sales and Support Offices.  
Figure E-1. CC Loop Compensation Curves for Models 6680A and 6681A  
126 Current Loop Compensation (Series 668xA Only)  
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Figure E-1. CC Loop Compensation Curves For Models 6682A and 6683A  
Current Loop Compensation (Series 668xA Only) 127  
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Figure E-1. CC Loop Compensation Curves For Model 6684A  
Setting The Loop Compensation Switch  
SHOCK/ENERGY HAZARD. This procedure involves removing the outside cover and should only  
be done by qualified electronics service personnel.  
1. Turn off the power switch and disconnect the power cord from the power source. If this is not possible, remove the three  
line fuses from the rear panel (see Figure 2-4).  
2. Remove the four screws that secure the two carrying straps and outside cover.  
3. Spread the bottom rear of the cover and pull it back to disengage it from the front panel.  
4. Remove the cover by sliding it back towards the rear of the supply.  
5. Locate the compensation switch (see Figure E-2).  
6. Move the switches to the desired position.  
7. Replace the outside cover.  
Figure E-2. CC Loop Compensation Switch  
128 Current Loop Compensation (Series 668xA Only)  
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F
Using Agilent 668xA Series Power Supplies in Autoparallel  
This information is supplementary to the information on page 80.  
A maximum of three Agilent 668xA series power supplies having thesame model number, may be configured for  
autoparallel operation. The Agilent 668xA power supplies were designed with an external programming offset so that the  
master unit will output current before the slave units do. Therefore, slave supplies will always sink current when low output  
current values are desired.  
Autoparallel Procedure  
1. Connect the Agilent 668xA power supplies with the Im terminal from the master connected to the +Ip terminal of each  
slave. Connect the ÏP terminal of the master to the -Ip terminal of each slave (see Figure 4-5e on page 81).  
2. Each load lead should be of the same wire gauge and length.  
3. Turn on all power supplies.  
4. Program each slave supply for zero (0) output current either by pressing [CURRENT ] [0] [ENTER] from the front panel  
keypad or sending the command "CURR:LEV 0" via the GPIB (see notes 2 and 3 on the follwing page).  
5. Program each slave’s output voltage at least 2 volts higher than the output voltage that the master supply will be  
programmed to.  
6. Program the master supply’s output current for a value slightly greater than one-half of the total desired output current if  
there is one slave supply, or one-third of the total desired output current if there are two slave supplies.  
7. Enable all power supplies by pressing the [Output On/Off ] key.  
8. Increase the master supply’s output voltage. At low output currents, the master unit will be supplyingall of the load  
current and the slave supplies will be sinking current, which is normal. At maximum output current each supply will be  
delivering an equal amount of output current. When operating at less than maximum current, it is normal to have unequal  
current sharing between the master and slave supplies. Current sharing among the supplies only becomes equal at  
maximum output current (see Figure F-1 ).  
9. For remote sensing, connect only the master supply’s +S and-S lines. Slave supplies should be connected for local  
sensing at the rear of their respective output terminals.  
Note 1  
The current division between the master and slaves can be determined as follows:  
Iout=Im [ 1 +Ns ( 1 +0.127V/5V)] - Ns Ifs (0.127V/5V)  
The amount of current the master unit must output before the slave units will output current can be determined as follows:  
Ns * Ifs (0.127V/5V)  
where Im = master current  
Ns = number of slaves  
Ifs = full scale current  
Example: 1 master unit, 2 slave units, Agilent Models 6680A (5V, 875A)  
Iout = Im ( 3.0508 ) - 44.4A  
Using Agilent 668xA Series Power Supplies in Autoparallel 129  
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The master current limit must be set above 44.4A /3.0508 = 14.55A to obtain any output current. For a no-load condition:  
Master current =14.55A  
Each slave current = -14.55A /2 = -7.28A  
Iout = 0A  
Note 2  
Note 3  
All Agilent 668xA power supplies have an output current programmed at power-on. The default current  
value programmed at power-on can be found in Table 3-1 of the Programming Guide (p/n 5960-5597).  
See *RST and *SAV in the Programming Guide to change the power-on current value.  
A current programmed via the rear panel +Ip or -Ip inputs will be summed with the current programmed  
via the front panel keypad or over the GPIB. When programming slave supplies via the rear panel +Ip or  
-Ip inputs, all slave current programming values must be zero (0 ).  
Figure F-1 Master/Slave Current Division  
130 Using Agilent 668xA Series Power Supplies in Autoparallel  
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Index  
A
ac disconnect switch (Series 668xA), 47  
air clearance, 44  
air fan, 50  
analog port, 58  
characteristics (see Supplemental Characteristics)  
connector configuration, 58  
signals, 58  
analog programming (see external voltage control)  
annunciators, 84  
Addr, 50, 84  
CC loop compensation (Series 668xA), 125  
CC mode, 19, 59, 60, 64, 68, 71, 74, 75, 78, 89, 90, 96,  
125  
CC operating line, 89  
checkout, 49  
output current, 52  
output voltage, 51  
power-on, 50  
preliminary, 49  
common commands (see the Programming Guide)  
Compatibility language (see the Programming Guide)  
Common P, 58, 66, 73  
CC, 17, 60, 84  
CV, 50, 84  
Cal, 84, 96  
connector, analog port, 58  
connector, digital port, 58, 122  
Current control, 52, 85, 88,  
current monitor, 58, 94, 97, 99, 106  
current monitoring resistor, 111, 114  
CV mode, 59, 65, 68, 75, 89, 96  
CV operating line, 89  
Dis, 50, 52, 53, 84  
Err, 84  
OCP, 52, 53, 84, 89  
Prot, 51, 52, 53, 84, 88, 120  
Rmt, 84  
Shift, 51, 84  
SRQ, 84  
Unr, 84, 90  
D
DFI, 15, 64, 72, 78, 79  
digital port, 122  
applications, 122  
configuration jumper, 121  
pin configuration, 119  
characteristics, 21  
B
battery charging  
with Series 664xA/665xA, 60  
with Series 667xA, 68  
with Series 668xA, 75  
disconnect box (see safety disconnect)  
downprogramming, 19  
C
calibration, 93  
default password, 94  
disabling, 94  
E
energy hazard, 52, 74, 88, 93, 116, 128  
error messages  
enabling, 96  
equipment required, 93  
jumper, 96, 97  
over GPIB, 98  
program for, 101  
SCPI commands for, 98  
setup, 95  
shunt resistor, 93  
calibrating  
current, 96  
calibration, 97  
OUT OF RANGE, 88  
power-on selftest, 55  
runtime, 56  
system (see the Programming Guide)  
exhaust fan, 44, 50, 53, 79  
external voltage control, 18  
Series 664xA/665xA, 65  
Series 667xA, 73  
current monitor (Series 668xA), 97  
OVP, 96  
Series 668xA, 79  
voltage, 96  
capacitive load  
Series 664xA/665xA, 59  
Series 667xA, 67  
Series 668xA, 74  
Index 131  
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F
H
FLT output, 18, 58, 119-121  
front panel, 83-86  
handles, rack, 16, 44  
hardware, 41  
front panel annunciators (see "annunciators")  
front panel data ENTRY keys, 85  
front panel keys, 84-86  
, 50, 85, 87, 88  
hazard, energy (see energy hazard)  
Agilent BASIC, 93, 101-102  
GPIB, 40  
address, 49-50, 53  
cables, 41  
capabilities, 40  
, 53, 85, 91  
, 99  
documents (see the Programming Guide)  
program errors (see the Programming Guide)  
, 86  
, 52, 85, 88, 90  
, 52, 85, 88  
I
52, 85, 88  
impedance, analog input, 58  
Series 664xA, 22  
Series 665xA, 27  
Series 667xA, 32  
Series 668xA, 36  
,
, 50, 88  
, 85  
, 85  
, 52-53, 85, 89  
, 50, 85, 87-89  
, 51, 85, 88  
, 51, 85, 88-89  
, 51, 85, 88-89  
, 53, 87, 90  
, 53, 56, 87, 90  
shift, 50, 87  
, 51, 52, 85, 87  
, 51, 85, 87  
, 51, 85, 87  
impedance, load (see load impedance)  
impedance, output, 19  
Series 664xA, 24  
Series 665xA, 29  
Series 667xA, 34  
Series 668xA, 39  
inductive load  
Series 665xA/665xA, 60  
Series 667xA, 67  
Series 668xA, 75, 125  
INH input, 58, 119-121  
input rail, 54, 116-117  
initial conditions (see turn-on conditions)  
isolation (see output isolation)  
front panel LCD, 84  
front panel LEDs (Series 668xA)  
Check Fuses, 49, 54-55, 86  
Dew, 49, 55, 86  
J
jumper  
front panel RPG controls, 85  
Current, 52, 85, 88  
Voltage, 51, 85, 87  
calibration, 96  
digital port configuration, 121  
local sense (Series 667xA), 67  
Series 664xA/665xA line voltage selection, 116  
Series 668xA line voltage selection, 118  
fuse, 41  
Series 664xA/665xA, 45, 49, 54  
Series 667xA, 45-46, 54  
Series 668xA, 17, 47, 54, 55, 117, 125, 129  
K
kit  
G
ground  
fuse replacement (Series 668xA), 17  
output connector (Series 668xA), 16, 77  
rack-mounting, 17, 44  
chassis, 66, 72, 79  
earth, 16, 46-48, 59, 68, 74  
signal, 61-62, 67, 69, 119  
132 Index  
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Series 664xA, 23  
Series 665xA, 28  
Series 667xA, 33  
Series 668xA, 38  
output isolation  
Series 664xA/665xA, 59  
Series 667xA, 66  
L
LED (see front panel LEDs)  
line cord  
Series 664xA/665xA, 45  
Series 667xA, 46  
Series 668xA, 48  
line fuse (see fuse)  
line phase balancing (Series 668xA), 47  
local voltage sensing  
Series 664xA/665xA, 60-61  
Series 667xA, 68  
Series 668xA, 74  
output impedance (see impedance, output)  
output queue (see the Programming Guide)  
OV, 16  
OVP operation, 88  
Series 668xA, 75  
load  
P
capacitive (see capacitive load)  
inductive (see inductive load)  
load line, 20  
load L/R ratio (Series 668xA), 125  
load ringing  
Series 664xA/665xA, 59-60  
Series 667xA, 67-68  
Series 668xA, 74-75  
load wire, 57  
packaging material, 44  
pack return system (Series 668xA), 44  
performance test, 49  
power cord (see line cord)  
power-on conditions (see turn-on conditions)  
power-on selftest, 49-50  
power options, 16  
power receptacle, 15  
power source, 16  
Series 664xA/665xA, 45  
Series 667xA, 45-46  
Series 668xA, 47-48  
M
manuals  
Programming Guide, 15, 41  
service, 41  
programming, 18  
accuracy (see Performance Specifications)  
analog (see external voltage control)  
parameters (see the Programming Guide)  
resolution (see Supplemental Characteristics)  
message, error (see error messages)  
message, PWR ON INIT, 50  
meter mode, 50  
monitor, current (see current monitor)  
R
N
recalling states, 53, 90  
register commands (see the Programming Guide)  
remote voltage sensing, 18  
nonvolatile memory, 18, 94  
Series 664xA, 22  
Series 665xA, 27  
Series 667xA, 32  
Series 668xA, 38  
and Series 664xA/665xA output noise, 61  
and Series 667xA output noise, 69  
and Series 668xA output noise, 76  
and Series 664xA/665xA output rating, 61  
and Series 667xA output rating, 69  
and Series 668xA output rating, 76  
and Series 664xA/665xA OVP operation, 61  
and Series 667xA OVP operation, 69  
and Series 668xA OVP operation, 76  
and Series 664xA/665xA output stability, 62  
and Series 667xA output stability, 69  
and Series 668xA output stability, 76  
Series 667xA bypass network, 69  
Series 668xA bypass network, 76  
O
OC, 18, 85, 89  
OCP operation, 89  
key (see front panel keys)  
operating features, 18  
OT, 18, 85  
Series 664xA/665xA, 64  
Series 667xA, 72  
Series 668xA, 79  
output characteristic, 87  
Index 133  
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resistor  
current monitoring (see current monitoring resistor)  
sense protect (Series 668xA), 76  
RI input, 18, 79, 120  
status (see the Programming Guide)  
subsystem commands (see the Programming Guide)  
switch, CC loop compensation, 125  
switch, sense (Series 664xA/665xA), 49, 59, 61  
support rails 17, 44  
reset conditions (see the Programming Guide)  
S
T
safety class, 16  
temperature characteristics (see applicable Supplemental  
Characteristics)  
safety compliance  
Series 664xA, 23  
Series 665xA, 28  
temperature, environment, 44, 57  
turn-on conditions, 95  
Series 667xA, 33  
Series 668xA, 38  
U
safety disconnect (Series 668xA), 47  
safety cover, ac input, 41  
safety warning, 16, 45, 46, 52, 54, 57, 59, 65, 67, 72, 74,  
79, 88, 115, 116, 117, 122, 128  
saving states, 53, 90  
SCPI (see the Programming Guide)  
serial number, 16  
service manual, 41  
specifications, 19  
Series 664xA, 20  
unregulated operation (Unr), 80, 85, 96  
Series 664xA/665xA, 61  
Series 667xA, 70  
Series 668xA, 75  
V
verification test, 111  
voltage sensing (see local voltage sensing or remote  
voltage sensing)  
Series 665xA, 25  
Series 667xA, 30  
W
warning (see safety warning)  
wire size, 57  
Series 668xA, 35  
supplemental characteristics, 19  
Series 664xA, 21-24  
Series 665xA, 26-29  
Series 667xA, 30-34  
Series 668xA, 36-40  
134 Index  
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Agilent Sales and Support Offices  
For more information about Agilent Technologies test and measurement products, applications, services, and for a current  
sales office listing, visit our web site: http://www.agilent.com/find/tmdir  
You can also contact one of the following centers and ask for a test and measurement sales representative.  
United States:  
Latin America:  
Agilent Technologies  
Test and Measurement Call Center  
P.O. Box 4026  
Englewood, CO 80155-4026  
(tel) 1 800 452 4844  
Agilent Technologies  
Latin American Region Headquarters  
5200 Blue Lagoon Drive, Suite #950  
Miami, Florida 33126  
U.S.A.  
(tel) (305) 267 4245  
(fax) (305) 267 4286  
Canada:  
Australia/New Zealand:  
Agilent Technologies Canada Inc.  
5150 Spectrum Way  
Mississauga, Ontario  
L4W 5G1  
Agilent Technologies Australia Pty Ltd  
347 Burwood Highway  
Forest Hill, Victoria 3131  
(tel) 1-800 629 485 (Australia)  
(fax) (61 3) 9272 0749  
(tel) 1 877 894 4414  
(tel) 0 800 738 378 (New Zealand)  
(fax) (64 4) 802 6881  
Europe:  
Asia Pacific:  
Agilent Technologies  
Test & Measurement European Marketing Organisation  
P.O. Box 999  
1180 AZ Amstelveen  
The Netherlands  
Agilent Technologies  
24/F, Cityplaza One, 1111 King’s Road,  
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tel: (852)-3197-7777  
fax: (852)-2506-9284  
(tel) (31 20) 547 9999  
Japan:  
Agilent Technologies Japan Ltd.  
Measurement Assistance Center  
9-1, Takakura-Cho, Hachioji-Shi,  
Tokyo 192-8510, Japan  
(tel) (81) 426 56 7832  
(fax) (81) 426 56 7840  
Technical data is subject to change.  
Agilent Sales and Support Offices 135  
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Manual Updates  
The following updates have been made to this manual since the print revision indicated on the title page.  
4/01/00  
All references to HP have been changed to Agilent.  
All references to HP-IB have been changed to GPIB.  
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