Keysight Technologies E3633A, E3634A Service Manual

Keysight E3633A and
E3634A DC Power Supplies

Service Guide

Notices

CAUTION

WARNING

Copyright Notice

© Keysight Technologies 1998 - 2019
No part of this manual may be repro-

duced in any form or by any means
(including electronic storage and
retrieval or translation into a foreign
language) without prior agreement and
written consent from Keysight Technol­ogies as governed by United States and
international copyright laws.

Manual Part Number

E3634-90010

Edition

Edition 9, March 26, 2019

Printed in:

Printed in Malaysia

Published by:

Keysight Technologies
Bayan Lepas Free Industrial Zone,
11900 Penang, Malaysia

Technology Licenses

The hardware and/or software
described in this document are fur­nished under a license and may be
used or copied only in accordance with
the terms of such license.

Declaration of Conformity

Declarations of Conformity for this
product and for other Keysight prod­ucts may be downloaded from the
Web. Go to http://www.keysight.com/

go/conformity. You can then search by

product number to find the latest Dec­laration of Conformity.

U.S. Government Rights

The Software is “commercial computer
software,” as defined by Federal Acqui­sition Regulation (“FAR”) 2.101. Pursu­ant to FAR 12.212 and 27.405-3 and
Department of Defense FAR Supple­ment (“DFARS”) 227.7202, the U.S.
government acquires commercial com­puter software under the same terms
by which the software is customarily
provided to the public. Accordingly,
Keysight provides the Software to U.S.
government customers under its stan­dard commercial license, which is
embodied in its End User License
Agreement (EULA), a copy of which can
be found at http://www.keysight.com/

find/sweula. The license set forth in the

EULA represents the exclusive authority
by which the U.S. government may use,
modify, distribute, or disclose the Soft­ware. The EULA and the license set
forth therein, does not require or per­mit, among other things, that Keysight:
(1) Furnish technical information
related to commercial computer soft­ware or commercial computer software
documentation that is not customarily
provided to the public; or (2) Relinquish
to, or otherwise provide, the govern­ment rights in excess of these rights
customarily provided to the public to
use, mod ify, reprod uce, release, per­form, display, or disclose commercial
computer software or commercial com­puter software documentation. No
additional government requirements
beyond those set forth in the EULA
shall apply, except to the extent that
those terms, rights, or licenses are
explicitly required from all providers of
commercial computer software pursu­ant to the FAR and the DFARS and are
set forth specifically in writing else­where in the EULA. Keysight shall be
under no obligation to update, revise or
otherwise modify the Software. With
respect to any technical data as
defined by FAR 2.101, pursuant to FAR

12.211 and 27.404.2 and DFARS

227.7102, the U.S. government
acquires no greater than Limited Rights
as defined in FAR 27.401 or DFAR

227.7103-5 (c), as applicable in any
technical data.

Warranty

THE MATERIAL CONTAINED IN THIS
DOCUMENT IS PROVIDED “AS IS,”
AND IS SUBJECT TO BEING
CHANGED, WITHOUT NOTICE, IN
FUTURE EDITIONS. FURTHER, TO THE
MAXIMUM EXTENT PERMITTED BY
APPLICABLE LAW, KEYSIGHT DIS­CLAIMS ALL WARRANTIES, EITHER
EXPRESS OR IMPLIED, WITH REGARD
TO THIS MANUAL AND ANY INFORMA­TION CONTAINED HEREIN, INCLUD­ING BUT NOT LIMITED TO THE
IMPLIED WARRANTIES OF MER­CHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE. KEYSIGHT
SHALL NOT BE LIABLE FOR ERRORS
OR FOR INCIDENTAL OR CONSE­QUENTIAL DAMAGES IN CONNECTION
WITH THE FURNISHING, USE, OR
PERFORMANCE OF THIS DOCUMENT
OR OF ANY INFORMATION CON­TAINED HEREIN. SHOULD KEYSIGHT
AND THE USER HAVE A SEPARATE
WRITTEN AGREEMENT WITH WAR­RANTY TERMS COVERING THE MATE­RIAL IN THIS DOCUMENT THAT
CONFLICT WITH THESE TERMS, THE
WARRANTY TERMS IN THE SEPARATE
AGREEMENT SHALL CONTROL.

Safety Information

A CAUTION notice denotes a hazard. It
calls attention to an operating proce­dure, practice, or the like that, if not
correctly performed or adhered to,
could result in damage to the product
or loss of important data. Do not pro­ceed beyond a CAUTION notice until
the indicated conditions are fully
understood and met.

A WARNING notice denotes a hazard. It
calls attention to an operating proce­dure, practice, or the like that, if not
correctly performed or adhered to,
could result in personal injury or death.
Do not proceed beyond a WARNING
notice until the indicated conditions are
fully understood and met.

2 Keysight E3633A and E3634A Service Guide

Safety Symbols

The following symbols on the instrument and in the documentation indicate
precautions which must be taken to maintain safe operation of the instrument.

Earth (ground) terminal Frame or chassis (ground) terminal

Caution, risk of danger (refer to this
manual for specific Warning or Caution
information)

Alternating current (AC) Protective earth (ground) terminal

Out position of a bi-stable push control In position of a bi-stable push control

Positive binding post Negative binding post

Direct current (DC)

Keysight E3633A and E3634A Service Guide 3

Regulatory Markings

This symbol is a South Korean Class A
EMC Declaration. This is a Class A
instrument suitable for professional
use and in electromagnetic
environment outside of the home.

This symbol indicates the time period
during which no hazardous or toxic
substance elements are expected to
leak or deteriorate during normal use.
Forty years is the expected useful life
of the product.

The CE mark is a registered trademark
of the European Community. This CE
mark shows that the product complies
with all the relevant European Legal
Directives.

This instrument complies with the
WEEE Directive (2002/96/EC) marking
requirement. This affixed product label
indicates that you must not discard
this electrical or electronic product in
domestic household waste.

The CSA mark is a registered
trademark of the Canadian
Standards Association.

ICES/NMB-001 indicates that this ISM
device complies with the
Canadian ICES-001.
Cet appareil ISM est conforme a la
norme NMB-001 du Canada.

The RCM mark is a registered
trademark of the Australian
Communications and Media Authority.

4 Keysight E3633A and E3634A Service Guide

Waste Electrical and Electronic Equipment (WEEE) Directive

This instrument complies with the WEEE Directive (2002/96/EC) marking
requirement. This affixed product label indicates that you must not discard this
electrical or electronic product in domestic household waste.

Product category:

With reference to the equipment types in the WEEE directive Annex 1, this
instrument is classified as a “Monitoring and Control Instrument” product.

The affixed product label is as shown below.

Do not dispose in domestic household waste.

To return this unwanted instrument, contact your nearest Keysight Service Center,
or visit http://about.keysight.com/en/companyinfo/environment/takeback.shtml
for more information.

Sales and Technical Support

To contact Keysight for sales and technical support, refer to the support links on
the following Keysight websites:

– www.keysight.com/find/powersupply

(product-specific information and support, software and
documentation updates)

– www.keysight.com/find/assist

(worldwide contact information for repair and service)

Keysight E3633A and E3634A Service Guide 5

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6 Keysight E3633A and E3634A Service Guide

Table of Contents

Safety Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Regulatory Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Waste Electrical and Electronic Equipment (WEEE) Directive . . . . . . . .5

Product category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Sales and Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

1Specifications

Performance Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Transient response time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Command processing time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

OVP and OCP accuracy, ±(% of output + offset) . . . . . . . . . . . . . . . .17

Activation time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Supplemental Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

Remote sensing capability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

Temperature coefficient, ±(% of output + offset) . . . . . . . . . . . . . . .18

Stability, ±(% of output + offset) . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Output voltage overshoot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Programming language . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

State Storage Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Recommended calibration interval . . . . . . . . . . . . . . . . . . . . . . . . . .19

Output Terminal Isolation (maximum, from chassis ground) . . . . . .19

AC input ratings (selectable via rear panel selector . . . . . . . . . . . . .20

Maximum input power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Operating temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Storage temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Environmental Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Weight (MY53xx6xxx) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Keysight E3633A and E3634A Service Guide 7

2Quick Start

Quick Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

To prepare the Power Supply for Use . . . . . . . . . . . . . . . . . . . . . . . . . . 26

To Check the Rated Voltages of the Power Supply . . . . . . . . . . . . . . . . 29

To Check the Rated Currents of the Power Supply . . . . . . . . . . . . . . . . 30

To Use the Power Supply in Constant Voltage Mode . . . . . . . . . . . . . . 32

To Use the Power Supply in Constant Current Mode . . . . . . . . . . . . . . 35

To store and Recall the Instrument State . . . . . . . . . . . . . . . . . . . . . . . 37

To Program Overvoltage Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

To Program Overcurrent Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

To Rack Mount the Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

3 Calibration Procedures

Keysight Technologies Calibration Services . . . . . . . . . . . . . . . . . . . . . 50

Calibration Interval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Automating Calibration Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Test Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Recommended Test Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Performance Verification Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Self-test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Performance verification tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Measurement Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Setup for most tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Electronic load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

General measurement techniques . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Current-Monitoring Resistor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

8 Keysight E3633A and E3634A Service Guide

Constant Voltage (CV) Verifications . . . . . . . . . . . . . . . . . . . . . . . . . . . .57

Constant voltage test setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57

Voltage programming and readback accuracy . . . . . . . . . . . . . . . . .57

CV load effect (load regulation) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

CV source effect (line regulation) . . . . . . . . . . . . . . . . . . . . . . . . . . .60

CV PARD (ripple and noise) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61

Load transient response time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62

Constant Current (CC) Verifications . . . . . . . . . . . . . . . . . . . . . . . . . . . .63

Constant current test setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63

Current programming and readback accuracy . . . . . . . . . . . . . . . . .63

CC load effect (load regulation) . . . . . . . . . . . . . . . . . . . . . . . . . . . .65

CC source effect (line regulation) . . . . . . . . . . . . . . . . . . . . . . . . . . .66

CC PARD (ripple and noise) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67

Common Mode Current Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68

Performance Test Record for Keysight E3633A and E3634A . . . . . . . .69

CV performance test record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69

CC performance test records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Calibration Security Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

To unsecure the power supply for calibration . . . . . . . . . . . . . . . . . .72

To unsecure the power supply without the security code . . . . . . . .74

Calibration Count . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Calibration Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76

General Calibration/ Adjustment Procedure . . . . . . . . . . . . . . . . . . . . .77

Front panel voltage and current calibration . . . . . . . . . . . . . . . . . . .78

Aborting a Calibration in Progress . . . . . . . . . . . . . . . . . . . . . . . . . . . . .83

Calibration Record for Keysight E3633A/E3634A . . . . . . . . . . . . . . . . .84

Error Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85

An Example Program of Excel 97 for Calibration . . . . . . . . . . . . . . . . . .88

Keysight E3633A and E3634A Service Guide 9

4Theory of Operation

Block Diagram Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

AC Input and Bias Supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

Floating Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

D-to-A Converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

A-to-D Converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

Power Mesh and Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

Earth-Referenced Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

5Service

Operating Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

Is the power supply inoperative? . . . . . . . . . . . . . . . . . . . . . . . . . . 110

Does the power supply fail self-test? . . . . . . . . . . . . . . . . . . . . . . . 110

Types of Service Available . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Standard repair service (worldwide) . . . . . . . . . . . . . . . . . . . . . . . . 111

Express Exchange (U.S.A. only) . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Repacking for Shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

Electrostatic Discharge (ESD) Precautions . . . . . . . . . . . . . . . . . . . . . 113

Surface Mount Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

To Replace the Power-Line Fuse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

To Disconnect the Output Using an External Relay . . . . . . . . . . . . . . 114

Installation Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

Troubleshooting Hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

Unit is inoperative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

Unit reports errors 740 to 750 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

Unit fails self-test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

Bias supplies problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

Self-Test Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

Power-on self-test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

Complete self-test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

10 Keysight E3633A and E3634A Service Guide

6 Component Drawings

E3633-60002/E3634-60002 Component Locator for

the Main Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .123

E3633-60003 Component Locator for the Front Panel . . . . . . . . . . . . 124

E3633-60019/E3634-60019 Component Locator for

the main board (serial MY53xx6xxx) . . . . . . . . . . . . . . . . . . . . . . . .125

Component Locator for the front panel (serial MY53xx6xxx) . . . . . . . .126

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12 Keysight E3633A and E3634A Service Guide

List of Figures

Figure 1-1 Dimensions of Keysight E3633A and E3634A

Figure 3-1 Performance verification test setup . . . . . . . . . . . . . . .54

Figure 3-2 Front panel terminal connections (side view) . . . . . . .55

Figure 3-3 Transient response time . . . . . . . . . . . . . . . . . . . . . . . .62

power supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

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14 Keysight E3633A and E3634A Service Guide

List of Tables

Table 1-1 Performance specifications . . . . . . . . . . . . . . . . . . . . . 16

Table 1-2 Supplemental Characteristics . . . . . . . . . . . . . . . . . . . 18

Table 3-1 Recommended test equipment . . . . . . . . . . . . . . . . . .52

Table 3-2 Parameters for calibration . . . . . . . . . . . . . . . . . . . . . .77

Table 5-1 Bias supplies voltages . . . . . . . . . . . . . . . . . . . . . . . . 116

Table 5-2 Bias supplies voltages . . . . . . . . . . . . . . . . . . . . . . . . 116

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16 Keysight E3633A and E3634A Service Guide

Keysight E3633A and E3634A DC Power Supplies
Service Guide

1 Specifications

Performance Specifications 18

Supplemental Characteristics 20

The performance specifications are listed in the following pages. Specifications
are warranted in the temperature range of 0 to 40°C with a resistive load.
Supplemental characteristics, which are not warranted but are descriptions of
performance determined either by design or testing. The Service Guide contains
procedures for verifying the performance specifications.

17

1 Specifications

Performance Specifications

Tab le 1-1 Performance specifications

Parameter Keysight E3633A Keysight E3634A

Output Ratings

°C- 40 °C)

(@ 0

Programming Accuracy

12 months (@ 25 °C ± 5 °C),
±(% of output + offset)

Readback Accuracy

12 months (over GPIB and
RS-232 or front panel with
respect to actual output @ 25 °C
± 5 °C), ±(% of output + offset)

Ripple and Noise

(with outputs ungrounded, or
with either output terminal
grounded, 20 Hz to 20 MHz)

Load Regulation,
±(% of output + offset)

Line Regulation,
±(% of output + offset)

Programming Resolution Voltage 1 mV 3 mV

Readback Resolution Voltage 0.5mV 1.5 mV

Front Panel Resolution Voltage 1 mV

[a]

[a][b]

Low Range 0 to +8 V/ 0 to 20 A 0 to 25 V/ 0 to 7 A

High Range 0 to +20V/ 0 to 10 A 0 to+50 V/ 0 to 4 A

Voltage 0.05% + 10 mV

Current 0.2% + 10 mA

Voltage 0.05% + 5 mV

Current 0.15% + 5 mA

Normal mode voltage <0.35 mV rms and

3 mV p-p

Normal mode current <2 mA rms

Common mode current <1.5 uA rms

Voltage <0.01% + 2 mV

Current

Voltage <0.01% + 2 mV

Current <0.01% + 250 μA

Current 1 mA 0.5 mA

Current 1 mA 0.5 mA

Current 1 mA (< 10A), 10mA (. 10A)

<0.01% + 250 μA

<0.5 mV rms and
3 mV p-p

[a] Accuracy specifications are after an 1-hour warm-up with no load and calibration at 25 °C.

[b] This specification may degrade when the unit is subjected to an RF field >= 3V/meter.

18 Keysight E3633A and E3634A Service Guide

Transient response time

Less than 50 μsec for output to recover to within 15 mV following a change in
output current from full load to half load or vice versa

Command processing time

Average time for output voltage to begin to change after receipt of digital data
when the power supply is connected directly to the GPIB or RS-232 is less than
100 msec

OVP and OCP accuracy, ±(% of output + offset)

OVP 0.5% + 0.5 V

OCP 0.5% + 0.5 A

Activation time

Specifications 1

Average time for output to start to drop after OVP and OCP condition occurs.

OVP <1.5 msec when the trip voltage is equal or greater than 3 V

<10 msec when the trip voltage is less than 3 V

OCP <10 msec

Keysight E3633A and E3634A Service Guide 19

1 Specifications

Supplemental Characteristics

Tab le 1-2 Supplemental Characteristics

Parameter Keysight E3633A Keysight E3634A

Output Programming Range

(maximum programmable values)

Voltage Programming Speed:

Maximum time required for output
voltage to settle within 1% of its total
excursion (for resistive load). Excludes

command processing time.

Remote sensing capability

Low Range

High Range

OVP 1 V to 22 V 1 V to 55 V

OCP 0 A to 22 A 0 A to 7.5 A

Up 95 msec 45 msec 80 msec 100 msec

Down 30 msec 450 msec 30 msec 450 msec

0 to +8.24 V/
0 to 20.6 A

0 to +20.6 V/
0 to 10.3 A

Full Load No Load Full Load No Load

0 to +25.75 V/
0 to 7.21 A

0 to +51.5V/
0 to 4.12 A

Voltage drop Up to 0.7 V per each lead

Load regulation

Load Voltage Subtract voltage drop in load leads from specified output voltage rating.

Add 5 mV to spec for each 1-volt change in the + output lead due to load
current changes

Temperature coefficient, ±(% of output + offset)

Maximum change in output/readback per °C after a 30-minute warm-up

Voltage 0.01% + 3 mV

Current 0.02% + 3 mA

20 Keysight E3633A and E3634A Service Guide

Stability, ±(% of output + offset)

Following a 30-minute warm-up, with the output in the ON state according to the
operating mode (CC with load or CV), and with a change in the output over 8
hours under constant load, line, and ambient temperature.

Voltage 0.02% + 1mV

Current 0.1% + 1mA

Output voltage overshoot

During turn-on or turn-off of ac power, output plus overshoot will not exceed 1 V
if the output control is set to less than 1 V. If the output control is set to 1 V or
higher, there is no overshoot.

Programming language

SCPI (Standard Commands for Programmable Instruments)

Specifications 1

State Storage Memory

Three (3) user-configurable stored states

Recommended calibration interval

1 year

Output Terminal Isolation (maximum, from chassis ground)

±60 Vdc when connecting shorting conductors without insulation to the
(+) output to the (+) sense and the (-) output and the (-) sense terminals.

±240 Vdc when connecting insulated shorting conductors to the (+) output
to the (+) sense and the (-) output and the (-) sense terminals.

Keysight E3633A and E3634A Service Guide 21

1 Specifications

AC input ratings (selectable via rear panel selector

Maximum input power

700 VA with full load

Cooling

Fan cooled.

Operating temperature

0 to 40 °C for full rated output. At higher temperatures, the output current is
derated linearly to 50% at 55 °C maximum temperature.

std 115 Vac ± 10%, 47 to 63 Hz

opt 0E3 230 Vac ± 10%, 47 to 63 Hz

opt 0E9 100 Vac ± 10%, 47 to 63 Hz

Storage temperature

-20 to 70 °C for storage environment.

Environmental Conditions

Designed for indoor use in an installation category II, pollution degree 2
environment. Designed to operate at a maximum relative humidity of 95 % and at
altitudes of up to 2000 meters.

Dimensions

[1] See below for detailed information

22 Keysight E3633A and E3634A Service Guide

[1]

213 mmW x 133 mmH x 348 mmD (8.4 x 5.2 x 13.7 in)

Weight

Net 9.5 kg (21 lb)

Shipping 12 kg (26 lb)

Weight (MY53xx6xxx)

Net 11.4 kg (E3633A)

10.9 kg (E3634A)

Shipping 13.9 kg (E3633A)

13.4 kg (E3634A)

Specifications 1

Figure 1-1 Dimensions of Keysight E3633A and E3634A power supplies

Keysight E3633A and E3634A Service Guide 23

1 Specifications

THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK.

24 Keysight E3633A and E3634A Service Guide

Keysight E3633A and E3634A DC Power Supplies
Service Guide

2 Quick Start

Quick StartQuick Start 26

To prepare the Power Supply for Use 28

To Check the Rated Voltages of the Power Supply 31

To Check the Rated Currents of the Power Supply 32

To Use the Power Supply in Constant Voltage Mode 34

To Use the Power Supply in Constant Current Mode 37

To store and Recall the Instrument State 39

To Program Overvoltage Protection 41

To Program Overcurrent Protection 45

To Rack Mount the Power Supply 49

25

2Quick Start

Quick Start

One of the first things you will want to do with your power supply is to become
acquainted with its front panel. Written procedures in this chapter prepare the
power supply for use and familiarize you with most front-panel operations.

– The power supply is shipped from the factory configured in the front-panel

– The power supply has two output ranges. This feature allows more voltage at a

– When you press key (the Limit annunciator blinks), the display of the

operation mode. At power-on, the power supply is automatically set to operate
in the front-panel operation mode. When in this mode, the front-panel keys
can be used. When the power supply is in remote operation mode, you can
return to front-panel operation mode at any time by pressing the (Local)
key if you did not previously send the front-panel lockout command. A change
between front-panel and remote operation modes will not result in a change in
the output parameters

lower current or more current at a lower voltage. The desired output range is
selected from the front panel or over the remote interfaces. The 8V or 20V for
the E3633A and 25V or 50V for the E3634A annunciator indicates the
presently selected range.

power supply goes to the limit mode and the present limit values will be
displayed. In this mode, you can also observe the change of the limit values

when adjusting the knob. If you press the key again or let the display
time-out after several seconds, the power supply will return the display to the
meter mode (the Limit annunciator turns off). In this mode, the actual output
voltage and current will be displayed.

– The output of the power supply can be enabled or disabled from the front

panel by pressing key. When the output is off, the OFF annunciator turns
on and the output is disabled.

26 Keysight E3633A and E3634A Service Guide

Quick Start 2

– The display provides the present operating status of the power supply with

annunciators and also informs the user of error codes. For example, the power

[1]

supply is operating in CV mode in the 8V/20A

or 25V/7A

controlled from the front panel, then the CV and 8V

[1]

[2]

or 25V

range and

[2]

annunciators

will turn on. If, however, the power supply is remotely controlled, the Rmt

annunciator will also turn on, and when the power supply is being addressed

over HPIB interface, the Adrs annunciator will turn on.

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

Keysight E3633A and E3634A Service Guide 27

2Quick Start

To prepare the Power Supply for Use

The following steps help you verify that the power supply is ready for use.

1 Check the list of supplied items.

Verify that you have received the following items with your power supply. If
anything is missing, contact your nearest Keysight Technologies Sales Office.

– One power cord for your location.

– This User’s Guide.

– One Service Guide.

– Certificate of Calibration.

2 Verify that the correct power-line voltage setting is selected and that the

correct power-line fuse is installed.

The line voltage is set to 100, 115 or 230 Vac from the factory according to the
input power option selected when you ordered the power supply. Change the
voltage setting if it is not correct for your location (see the next page for
detailed information). For 100 or 115 Vac operation, the correct fuse is 6.3 AT
(Keysight part number 2110-1030) and for 230 Vac operation, the correct fuse
is 3.15 AT (Keysight part number 2110-1031).

3 Connect the power cord and turn on the power supply.

A power-on self-test occurs automatically when you turn on the power supply.
The front-panel display will light up while the power supply performs its
power-on self- test. After performing the self-test, the power supply will go
into the power-on / reset state; the output is disabled (the OFF annunciator

turns on); the 8V/20A

[1]

or 25V/7A

[2]

range is selected (the 8V

[1]

or 25V

[2]

annunciator turns on); the knob is selected for voltage control.

Notice that the OVP and OCP annunciators also turn on.

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

28 Keysight E3633A and E3634A Service Guide

Quick Start 2

4 Enable the outputs.

Press key to enable the outputs. The OFF annunciator turns off and the

8V

[1]

or 25V

[2]

, OVP, OCP, and CV annunciators are lit. The blinking digit can be

adjusted by turning the knob. Notice that the display is in the meter mode.

“Meter mode” means that the display shows the actual output voltage and

current.

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

Keysight E3633A and E3634A Service Guide 29

2Quick Start

NOTE

1 Remove the power cord. Remove the fuse-holder assembly
with a flat-blade screwdriver from the rear panel.

3 Rotate the power-line vol tage selector until the correct
voltage appears.

2 Install the correct line fuse. Remove the power-line
voltage selector from the power-line module.

4 Replace the power-line voltage selector and the
fuse-holder assembly in the rear panel.

Install the correct fuse and verify that the correct line voltage appears in the
window.

30 Keysight E3633A and E3634A Service Guide

To Check the Rated Voltages of the Power Supply

NOTE

The following procedures check to ensure that the power supply produces its
rated voltage output with no load and properly responds to operation from the
front panel.

For each step, use the keys shown on the left margins.

1Turn on the power supply

The power supply will go into the power-on / reset state; the output is disabled

(the OFF annunciator turns on); the 8V/20A

(the 8V

[1]

or 25V

[2]

annunciator turns on); and the knob is selected for voltage

control.

2 Enable the outputs.

The OFF annunciator turns off and the 8V

annunciators are lit. The blinking digit can be adjusted by turning the knob.

Notice that the display is in the meter mode. “Meter mode” means that the

display shows the actual output voltage and current.

[1]

or 25V/7A

[1]

or 25V

[2]

Quick Start 2

[2]

range is selected

OVP, OCP, and CV

3 Check that the front-panel voltmeter properly responds to knob control for

the 8V/20A

[1]

or 25V/7A

[2]

range.

Turn the knob clockwise or counter clockwise to check that the voltmeter

responds to knob control and the ammeter indicates nearly zero.

4 Ensure that the voltage can be adjusted from zero to the full rated value.

Adjust the knob until the voltmeter indicates 0 volts and then adjust the knob

until the voltmeter indicates “8.0 volts”

[1]

or “25.0 volts”

[2]

You can use the resolution selection keys to move the flashing digit to the right
or left when setting the voltage.

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

Keysight E3633A and E3634A Service Guide 31

2Quick Start

To Check the Rated Currents of the Power Supply

The following steps check basic current functions with a short across the power
supply’s output.

1 Turn on the power supply.

The power supply will go into the power-on / reset state; the output is disabled

[1]

(the OFF annunciator turns on); the 8V/20A
(the 8V

[1]

or 25V

[2]

annunciator turns on); and the knob is selected for voltage

control.

2 Connect a short across (+) and (-) output terminals with an insulated test

lead.

3 Enable the output

The OFF annunciator turns off and the 8V
annunciators turn on. The CV or CC annunciator is lit depending on the
resistance of the test lead. The flashing digit can be adjusted by turning the
knob. Notice that the display is in the meter mode. “Meter mode” means that
the display shows the actual output voltage and current.

or 25V/7A

[1]

or 25V

[2]

[2]

range is selected

, OVP, and OCP

4 Adjust the voltage limit to 1.0 volt

Set the display to the limit mode (the Limit annunciator will be flashing).
Adjust the voltage limit to 1.0 volt to assure CC operation. The CC annunciator
will light.

5 Check that the front-panel ammeter properly responds to knob control.

Set the knob to the current control, and turn the knob clockwise or counter
clockwise when the display is in the meter mode (the Limit annunciator is off).
Check that the ammeter responds to knob control and the voltmeter indicates
nearly zero (actually, the voltmeter will show the voltage drop caused by the
test lead)

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

32 Keysight E3633A and E3634A Service Guide

Quick Start 2

NOTE

6 Ensure that the current can be adjusted from zero to the full rated value.

Adjust the knob until the ammeter indicates 0 amps and then until the

ammeter indicates 20.0 amps

[1]

or 7.0 amps

[2]

.

If an error has been detected during the output checkout procedures, the
ERROR annunciator will turn on. See “Error Messages’’ for more information,

starting on page 123 in chapter 5 of the User’s Guide.

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

Keysight E3633A and E3634A Service Guide 33

2Quick Start

NOTE

To Use the Power Supply in Constant Voltage Mode

To setup the power supply for constant voltage (CV) operation, proceed as
follows.

For each step, use the keys shown on the left margin.

1 Connect a load to the output terminals

With the power-off, connect a load to the (+) and (-) output terminals.

2 Turn on the power supply

The power supply will go into the power-on / reset state; the output is disabled
(the OFF annunciator turns on); the 8V/20A
(the 8V

[1]

or 25V

control. Press

[2]

annunciator turns on); and the knob is selected for voltage

[1]

or

[2]

key to operate the power supply in the 20V/

10A* or 50V/4A** range before proceeding to the next step. The 20V

[2]

annunciator turns on.

50V

3 Set the display to the limit mode

[1]

or 25V/7A

[2]

range is selected

[1]

or

Notice that the Limit annunciator blinks, indicating that the display is in the
limit mode. When the display is in the limit mode, you can see the voltage and
current limit values of the power supply.

In constant voltage mode, the voltage values between the meter and limit
modes are the same, but the current values are not. Moreover, if the display is in
the meter mode, you cannot see the change of current limit value when
adjusting the knob. We recommend that you should set the display to “limit”
mode to see the change of current limit value in the constant voltage mode
whenever adjusting the knob.

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

34 Keysight E3633A and E3634A Service Guide

Quick Start 2

4 Adjust the knob for the desired current limit.

Check that the Limit annunciator still blinks. Set the knob for current control.

The second digit of the ammeter will be blinking. The blinking digit can be

changed using the resolution selection keys and the blinking digit can be

adjusted by turning the knob. Adjust the knob to the desired current limit.

5 Adjust the knob for the desired output voltage.

Check that the Limit annunciator still blinks. Set the knob for voltage control.

The second digit of the voltmeter will be blinking. Change the blinking digit

using the resolution selection keys and adjust the knob to the desired output

voltage.

6 Return to the meter mode.

Press key or let the display time-out after several seconds to return to

the meter mode. Notice that the Limit annunciator turns off and the displays

shows “OUTPUT OFF” message.

7 Enable the output.

The OFF annunciator turns off and the 8V

[1]

(or 25V

[2]

) or 20V

[1]

(or 50V

OVP, OCP and CV annunciators are lit. Notice that the display is in the meter

mode. In the meter mode, the display shows the actual output voltage and

current.

[2]

),

8 Verify that the power supply is in the constant voltage mode.

If you operate the power supply in the constant voltage (CV) mode, verify that

the CV annunciator is lit. If the CC annunciator is lit, choose a higher current

limit.

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

Keysight E3633A and E3634A Service Guide 35

2Quick Start

NOTE

NOTE

During actual CV operation, if a load change causes the current limit to be
exceeded, the power supply will automatically crossover to the constant current
mode at the preset current limit and the output voltage will drop
proportionately.

You can use the resolution selection keys to move the flashing digit to the right
or left when setting the current.

36 Keysight E3633A and E3634A Service Guide

To Use the Power Supply in Constant Current Mode

NOTE

To set up the power supply for constant current (CC) operation, proceed as
follows.

1 Connect a load to the output terminals.

With power-off, connect a load to the (+) and (-) output terminals.

2Turn on the power supply

The power supply will go into the power-on / reset state; the output is disabled

(the OFF annunciator turns on); the 8V/20A

(the 8V

[1]

or 25V

[2]

annunciator turns on); and the knob is selected for voltage

control.

[1]

Press

[2]

50V

or

annunciator turns on.

[2]

key before proceeding to the next step. The 20V

3 Set the display to the limit mode.

[1]

or 25V/7A

Quick Start 2

[2]

range is selected

[1]

or

Notice that the Limit annunciator blinks, indicating that the display is in the

limit mode. When the display is in the limit mode, you can see the voltage and

current limit values of the selected supply.

In constant current mode, the current values between the meter mode and limit
mode are the same, but the voltage values are not. Moreover, if the d isplay is in
the meter mode, you cannot see the change of voltage limit value when
adjusting the knob. We recommend that you should set the display to “limit”
mode to see the change of voltage limit value in the constant current mode
whenever adjusting the knob.

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

Keysight E3633A and E3634A Service Guide 37

2Quick Start

NOTE

4 Adjust the knob for the desired voltage limit.

5 Adjust the knob for the desired output current.

6 Return to the meter mode.

7 Enable the output.

Check that the Limit annunciator still blinks and the second digit of voltmeter
blinks to indicate the knob is selected for voltage control.The blinking digit can
be changed using the resolution keys and the blinking digit can be adjusted by
turning the knob. Adjust the knob for the desired voltage limit.

Check that the Limit annunciator still blinks. Set the knob for current control.
The second digit of the ammeter will be blinking. Change the blinking digit
using the resolution selection keys and adjust the knob to the desired output
current.

Press key or let the display time-out after several seconds to return to
the meter mode. Notice that the Limit annunciator turns off and the display
shows “OUTPUT OFF” message.

The OFF annunciator turns off and the 8V

[1]

(or 25V

[2]

) or 20V

[1]

(or 50V

[2]

),

OVP, OCP and CC annunciators are lit. Notice that the display is in the meter
mode. In the meter mode, the display shows the actual output voltage and
current.

8 Verify that the power supply is in the constant current mode.

If you operate the power supply in the constant current (CC) mode, verify that
the CC annunciator is lit. If the CV annunciator is lit, choose a higher voltage
limit.

During actual CC operation, if a load change causes the voltage limit to be
exceeded, the power supply will automatically crossover to constant voltage
mode at the preset voltage limit and the output current will drop
proportionately.

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

38 Keysight E3633A and E3634A Service Guide

To store and Recall the Instrument State

You can store up to three different operating states in non-volatile memory. This
also enables you to recall the entire instrument configuration with just a few key
presses from the front panel.

The memory locations are supplied with the reset states from the factory for
front-panel operation. Refer to the description of *RST command, starting on

page 84 in chapter 4 for more information. The following steps show you how to

store and recall an operating state.

1 Set up the power supply for the desired operating state.

The storage feature “remembers” output range selection, the limit value

settings of voltage and current, output on/off state, OVP and OCT on/off state

and OVP and OCP trip levels.

2 Turn on the storage mode.

Three memory locations (numbered 1, 2 and 3) are available to store the

operating states. The operating states are stored in non-volatile memory and

are remembered when being recalled.

Quick Start 2

STORE 1

This message appears on the display for approximately 3 seconds.

3 Store the operating state in memory location “3”.

Turn the knob to the right to specify the memory location 3.

STORE 3

To cancel the store operation, let the display time-out after about 3 seconds

or press any other function key except the ion key except the key. The

power supply returns to the normal operating mode and to the function

pressed. Save the operating state.

Keysight E3633A and E3634A Service Guide 39

2Quick Start

4 Save the operating state.

5 Turn on the recall mode.

6 Recall the stored operating state.

The operating state is now stored. To recall the stored state, go to the
following steps.

DONE

Memory location “1” will be displayed in the recall mode.

RECALL 1

This message appears on the display for approximately 3 seconds.

Turn the knob to the right to change the displayed storage location to 3.

RECALL 3

If this setting is not followed within 3 seconds with key stroke, the power
supply returns to normal operating mode and will not recall the instrument
state 3 from memory.

7 Restore the operating state.

The power supply should now be configured in the same state as when you
stored the state on the previous steps.

DONE

This message appears on the display for approximately 1 second.

40 Keysight E3633A and E3634A Service Guide

To Program Overvoltage Protection

Overvoltage protection guards the load against output voltages that reach a
specified value greater than the programmed protection level. It is accomplished
by shorting the output via an internal SCR when the trip level is set to equal or
greater than 3 volts, or by programming the output to 1 volt when the trip level is
set to less than 3 volts.

The following steps show how to set the OVP trip level, how to check OVP
operation, and how to clear overvoltage condition.

Setting the OVP level and enable the OVP circuit

1Turn on the power supply.

The power supply will go into the power-on / reset state; the output is disabled

(the OFF annunciator turns on); the 8V/20A

(the 8V

[1]

or 25V

control.

2 Enable the output.

The OFF annunciator turns off and the display will go to the meter mode.

[2]

annunciator turns on); and the knob is selected for voltage

[1]

or 25V/7A

Quick Start 2

[2]

range is selected

3 Enter the OVP menu and set the trip level.

LEVEL 22.0V (E3633A)

LEVEL 55.0V (E3634A)

You will see the above message on the display when you enter the OVP menu.

Adjust the control knob for the desired OVP trip level.

Note that you cannot set the trip levels to lower than 1.0 volt.

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

Keysight E3633A and E3634A Service Guide 41

2Quick Start

4 Enable the OVP circuit.

5Exit the OVP menu.

Checking OVP operation

To check OVP operation, raise the output voltage to near the trip point. Then very
gradually increase the output by turning the knob until the OVP circuit trips. This
will cause the power supply output to drop to near zero, the OVP annunciator to
blink, and the CC annunciator to turn on. The “OVP TRIPPED” message also
appears on the display.

OVP ON

You will see the above message after pressing key.

CHANGED

The “CHANGED” message is highlighted for a second to show that the new
OVP trip level is now in effect. If the OVP settings are not changed, “NO
CHANGE” will be displayed. The power supply will exit the OVP menu and the
display will return to the meter mode. Check that the OVP annunciator turns
on.

Clearing the overvoltage condition

When the OVP condition occurs (the “OVP TRIPPED” message is shown on the
display), the OVP annunciator blinks. When it was caused by an external voltage
source such as a battery, disconnect it first. Clear the overvoltage condition by
adjusting output voltage level or by adjusting OVP trip level.

The following steps show how to clear the overvoltage condition and get back to
normal mode operation. In the following steps, the display will go back to “OVP
TRIPPED” if you let the display time out after about several seconds.

42 Keysight E3633A and E3634A Service Guide

Quick Start 2

– Adjust the output voltage level

1 Lower the output voltage level.

Lower the output voltage level below the OVP trip point after pressing
key. The OVP and Limit annunciators are blinking.

2 Move to the clear mode.

OVP CLEAR

Press key twice to move to the OVP CLEAR mode. The “OVP ON”
message appears on the display. Turn the knob to the right until the above
message appears on the display.

3 Clear the overvoltage cond ition and exit this menu.

Now, when you press key again, the “DONE” message is displayed for
a second and the OVP annunciator will not blink any more. The output will
return to meter mode.

Keysight E3633A and E3634A Service Guide 43

2Quick Start

– Adjust OVP trip level

1Raise the OVP trip level.

Press key and turn the knob to raise the OVP trip level.

2 Move to the OVP CLEAR mode.

OVP CLEAR

Press key to move the OVP clear mode. The “OVP ON” message
appears on the display. Turn the knob to the right until the above message
appears on the display.

3 Clear the overvoltage condition and exit this menu.

Now, when you press key again, the “DONE’’ message is displayed for
a second and the OVP annunciator will not blink any more. The output will
return to the meter mode.

44 Keysight E3633A and E3634A Service Guide

To Program Overcurrent Protection

Overcurrent protection guards the load against output currents that reach a
specified value greater than the programmed protection level. It is accomplished
by programming the output current to zero.

The following steps show how to set the overcurrent protection trip level, how to
check OCP operation and how to clear overcurrent condition.

Setting the OCP level and enable the OCP circuit

1Turn on the power supply.

The power supply will go into the power-on / reset state; the output is disabled

(the OFF annunciator turns on); the 8V/20A

(the 8V

[1]

or 25V

control.

2 Enable the output.

The OFF annunciator turns off and the display will go to the meter mode.

[2]

annunciator turns on); and the knob is selected for voltage

[1]

or 25V/7A

Quick Start 2

[2]

range is selected

3 Enter the OCP menu and set the trip level.

LEVEL 22.0 A (E3633A)

LEVEL 7.5 A (E3634A)

You will see the above message on the display when you enter the OCP menu.

Adjust the knob for the desired OCP trip level.

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

Keysight E3633A and E3634A Service Guide 45

2Quick Start

4Enable the OCP circuit

5 Exit the OCP menu.

Checking OCP operation

To check OCP operation, raise the output current to near the trip point. Then very
gradually increase the output by turning the knob until the OCP circuit trips. This
will cause the power supply’s output current to drop to zero and the OCP
annunciator to blink. The “OCP TRIPPED” message also appears on the display.

OCP ON

You will see the above message after pressing the key.

CHANGED

The “CHANGED” message is displayed for a second to show that the new OCP
trip level is now in effect. If the OCP settings are not changed, “NO CHANGE”
will be displayed. The power supply will exit the OCP menu and the display will
return to the meter mode. Check that the OCP annunciator turns on.

Clearing the overcurrent condition

When the OCP condition occurs (the “OCP TRIPPED” message is shown on the
display), the OCP annunciator blinks. When it was caused by external voltage
sources such as a battery, disconnect it first. Clear the overcurrent condition by
adjusting output current level or by adjusting OCP trip level.

The following steps show how to clear the overcurrent condition and get back to
normal mode operation. In the following steps, the display will go back to “OCP
TRIPPED” if you let the display time out after about several seconds.

46 Keysight E3633A and E3634A Service Guide

Quick Start 2

– Adjust output current level

1 Lower the output current level.

Press key and set the knob for current control by pressing key
then lower the output current level below the OCP trip point.

2 Move to the clear mode.

OCP CLEAR

Press key twice to move to the OCP CLEAR mode. The “OCP ON”
message appears on the display. Turn the knob to the right until the above
message appears on the display

3 Clear the overcurrent condition and exit this menu.

Now, when you press key again, the “DONE” message is displayed for
a second and the OCP annunciator will not blink any more. The output will
return to meter mode. The knob is selected for current control.

Notice that the power supply is operated in the constant current (CC)
mode.

Keysight E3633A and E3634A Service Guide 47

2Quick Start

– Adjust OCP trip level

1 Raise the OCP trip level.

Press key and turn the knob to raise the OCP trip level.

2 Move to the OCP CLEAR mode.

OCP CLEAR

Press the key to move to the OCP CLEAR mode. The “OCP ON” message
appears on the display. Turn the knob to the right until the above message
appears on the display.

3 Clear the overcurrent condition and exit this menu.

Now, when you press again, the “DONE” message is displayed for a
second and the OCP annunciator will not blink any more. The output will
return the meter mode.

48 Keysight E3633A and E3634A Service Guide

To Rack Mount the Power Supply

The power supply can be mounted in a standard 19-inch rack cabinet using one of
three optional kits available. A rack-mounting kit for a single instrument is
available as Option 1CM (P/N 5063-9243). Installation instructions and hardware
are included with each rack-mounting kit. Any Keysight System II instrument of
the same size can be rack-mounted beside the Keysight E3633A or E3634A DC
power supply.

Remove the front and rear bumpers before rack-mounting the power supply.

Quick Start 2

To remove the rubber bumper, pull the bumper off from the top as there are
protrusions on the sides and bottom of the cover.

To rack mount a single instrument, order adapter kit 5063-9243.

Keysight E3633A and E3634A Service Guide 49

2Quick Start

To rack mount two instruments of the same depth side-by-side, order lock-link
kit 5061-9694 and flange kit 5063-9214.

To install two instruments in a sliding support shel f, order support shel f
5063-9256, and slide kit 1494-0015.

50 Keysight E3633A and E3634A Service Guide

Keysight E3633A and E3634A DC Power Supplies
Service Guide

3 Calibration Procedures

Keysight Technologies Calibration Services 52

Calibration Interval 52

Automating Calibration Procedures 53

Test Considerations 53

Recommended Test Equipment 54

Performance Verification Tests 55

Measurement Techniques 56

Constant Voltage (CV) Verifications 59

Constant Current (CC) Verifications 65

Common Mode Current Noise 70

Performance Test Record for Keysight E3633A and E3634A 71

Calibration Security Code 73

Calibration Count 77

Calibration Message 78

General Calibration/ Adjustment Procedure 79

Aborting a Calibration in Progress 85

Calibration Record for Keysight E3633A/E3634A 86

Error Messages 87

An Example Program of Excel 97 for Calibration 90

This chapter contains procedures for verification of the power supply’s
performance and calibration (adjustment).

The performance verification tests for constant voltage (CV) and constant current
(CC) operations use the power supply’s specifications listed in “Specifications” on
page 17.

51

3 Calibration Procedures

NOTE

If you calibrate the power supply over the remote interface, you must send the

*RST

command to the power supply or turn the power supply off and on again

after performing a calibration to ensure proper power supply operation.

Closed-Case Electronic Calibration

The power supply features closed-case electronic calibration since no internal
mechanical adjustments are required for normal calibration. The power supply
calculates correction factors based upon the input reference value you enter. The
new correction factors are stored in non-volatile memory until the next calibration
adjustment is performed. (Non-volatile memory does not change when power has
been off or after a remote interface reset.)

Keysight Technologies Calibration Services

When your power supply is due for calibration, contact your local Keysight
Technologies Service Center for a low-cost calibration. The Keysight E3633A and
E3634A power supplies are supported on calibration processes which allow
Keysight Technologies to provide this service at competitive prices.

Calibration Interval

The power supply should be calibrated on a regular interval determined by the
accuracy requirements of your application. A 1-year interval is adequate for most
applications. Keysight Technologies does not recommend extending calibration
intervals beyond 1 year for any application. Keysight Technologies recommends
that complete re-adjustment should always be performed at the calibration
interval. This will increase your confidence that the Keysight E3633A and E3634A
will remain within specification for the next calibration interval. This criteria for
re-adjustment provides the best long-term stability.

52 Keysight E3633A and E3634A Service Guide

Automating Calibration Procedures

CAUTION

You can automate the complete verification procedures outlined in this chapter if
you have access to programmable test equipment. You can program the
instrument configurations specified for each test over the remote interface. You
can then enter readback verification data into a test program and compare the
results to the appropriate test limit values.

You can also enter calibration constants from the remote interface. Remote
operation is similar to the local front-panel procedure. You can use a computer to
perform the adjustment by first selecting the required setup. The calibration value
is sent to the power supply and then the calibration is initiated over the remote
interface. The power supply must be unsecured prior to initiating the calibration
procedure. An example program of Excel 97 for calibration over the GPIB interface
is listed at the end of this chapter.

For further details on programming the power supply, see chapters 3 and 4 in the
Keysight E3633A and E3634A User’s Guide.

Test Considerations

Calibration Procedures 3

To ensure proper instrument operation, verify that you have selected the correct
power-line voltage prior to attempting any test procedure in this chapter. See

page 30 in Chapter 2 for more information.

Ensure that all connections of terminals (both front panel and rear panel) are
removed while the power supply internal self-test is being performed.

For optimum performance verification, all test procedures should comply with the
following recommendations:

– Assure that the calibration ambient temperature is stable and between 20°C

and 30°C.

– Assure ambient relative humidity is less than 80%.

– Allow a 1-hour warm-up period before verification or calibration.

– Use short cables to connect test set-ups.

The tests should be performed by qualified personnel. During performance
verification tests, hazardous voltages may be present at the outputs of the
power supply.

Keysight E3633A and E3634A Service Guide 53

3 Calibration Procedures

Recommended Test Equipment

The test equipment recommended for the performance verification and
adjustment procedures is listed below. If the exact instrument is not available, use
the accuracy requirements shown to select substitute calibration standards. If you
use equipment other than that recommended in Table 3-1, you must recalculate
the measurement uncertainties for the actual equipment used.

Tab le 3-1 Recommended test equipment

Instrument Requirements Recommended

Model

GPIB controller Full GPIB or RS-232 capabilities Keysight 82341C

interface card

Oscilloscope 100 MHz with 20 MHz

bandwidth

RMS voltmeter 20 Hz to 20 MHz Measure rms ripple & noise

Coaxial cable Keysight 10502A Measure rms ripple & noise

BNC female to
banana plug
adapter

Digital voltmeter Resolution: 0.1 mV

Accuracy: 0.01%

Electronic load Voltage range: 60 Vdc

Current range: 60 Adc
Open and short switches
Transient on/off

Resistive loads
(RL)

Current
monitoring
resistor (shunt)

(0.4 Ω, 300 W/2.0 Ω, 300 W)
(3.5 Ω, 300 W/12.5 Ω, 300 W)

(0.01 Ω, 0.1%)

[c]

Keysight 54602B Display transient response

Keysight
1251-2277

Keysight 34401A Measure dc voltages

Keysight 60502B Measure load and line

[a]

[b]

ISOTEK Co.
Model: A-H

Programming and readback
accuracy

and ripple & noise waveform

Measure rms ripple & noise

regulations and transient
response time.

Measure rms ripple & noise

Constant current test setup

Use

[a] For Keysight E3633A Model

[b] For Keysight E3634A Model

[c] It is recommended to use a current monitoring resistor after calibration to find the accurate resistance.

54 Keysight E3633A and E3634A Service Guide

Performance Verification Tests

The performance verification tests use the power supply’s specifications listed in

“Specifications” on page 17.

You can perform two different levels of performance verification tests:

– Self-Test

A series of internal verification tests that provide high confidence that the

power supply is operational.

– Performance Verification Tests

These tests are used to verify that the power supply is operating as specified in

the performance specifications.

Self-test

A power-on self-test occurs automatically when you turn on the power supply.
This limited test assures you that the power supply is operational.

The complete self-test is enabled by holding down key (actually any front
panel keys except key) as you turn on the power supply and hold down the

key until you hear a long beep. The self-test will begin when you release the key
following the beep. The complete self-test takes approximately two seconds to
execute.

You can also perform a self-test from the remote interface (see chapter 3 in the
Keysight E3633A and E3634A User’s Guide).

– If the self-test is successful, “PASS” is displayed on the front panel.

Calibration Procedures 3

– If the self-test fails, “FAIL” is displayed and the ERROR annunciator turns on. If

repair is required, see chapter 5, “Service”, for further details.

– If self-test passes, you have a high confidence that the power supply is

operational.

Performance verification tests

These tests should be used to verify the power supply’s specifications following
repairs to specific circuits. The following sections explain all verification
procedures in detail. All of the performance test limits are shown in each test.

Keysight E3633A and E3634A Service Guide 55

3 Calibration Procedures

Measurement Techniques

Setup for most tests

Most tests are performed at the front terminals as shown in the following figure.
Measure the dc voltage directly at the (+) and (–) terminals on the front panel.

Figure 3-1 Performance verification test setup

Electronic load

Many of the test procedures require the use of a variable load resistor capable of
dissipating the required power. Using a variable load resistor requires that
switches should be used to connect, disconnect, and short the load resistor. An
electronic load, if available, can be used in place of a variable load resistor and
switches. The electronic load is considerably easier to use than load resistors. It
eliminates the need for connecting resistors or rheostats in parallel to handle
power, it is much more stable than carbon-pile load, and it makes easy work of
switching between load conditions as is required for the load regulation and load
response tests. Substitution of the electronic load requires minor changes to the
test procedures in this chapter.

56 Keysight E3633A and E3634A Service Guide

General measurement techniques

To achieve best results when measuring load regulation, peak to peak voltage,
and transient response time of the power supply, measuring devices must be
connected through the hole in the neck of the binding post at (A) while the load
resistor is plugged into the front of the output terminals at (B). A measurement
made across the load includes the impedance of the leads to the load. The
impedance of the load leads can easily be several orders of the magnitude greater
than the power supply impedance and thus invalidate the measurement. To avoid
mutual coupling effects, each measuring device must be connected directly to the
output terminals by separate pairs of leads.

Calibration Procedures 3

Figure 3-2 Front panel terminal connections (side view)

Current-Monitoring Resistor

To eliminate output current measurement error caused by the voltage drops in the
leads and connections, connect the current monitoring resistor between the (-)
output terminal and the load as a four-terminal device. Connect the
current-monitoring leads inside the load-lead connections directly at the
monitoring points on the resistor element (see R

Keysight E3633A and E3634A Service Guide 57

in Figure 3-1).

M

3 Calibration Procedures

Programming

Most performance tests can be performed from the front panel. However, an GPIB
or RS-232 controller is required to perform the voltage and current programming
accuracy and readback accuracy tests.

The test procedures are written assuming that you know how to program the
power supply either from the front panel or from an GPIB or RS-232 controller.
Complete instructions on front panel and remote programming are given in the

Keysight E3633A and E3634A User’s Guide.

58 Keysight E3633A and E3634A Service Guide

Constant Voltage (CV) Verifications

Constant voltage test setup

If more than one meter or if a meter and an oscilloscope are used, connect each to
the (+) and (–) terminals by a separate pair of leads to avoid mutual coupling
effects. Use coaxial cable or shielded 2-wire cable to avoid noise pick-up on the
test leads.

Voltage programming and readback accuracy

This test verifies that the voltage programming and GPIB or RS-232 readback
functions are within specifications. Note that the readback values over the remote
interface should be identical to those displayed on the front panel.

You should program the power supply over the remote interface for this test to
avoid round off errors.

1 Turn off the power supply and connect a digital voltmeter between the (+) and

(–) terminals of the output to be tested as shown in Figure 3-1

2 Turn on the power supply. Select the 20V/10A

enable the output by sending the commands:

Calibration Procedures 3

[1]

or 50V/4A

[2]

range and

VOLT:RANG P20V (E3633A)

VOLT:RANG P50V (E3634A)

OUTP ON

3 Program the output voltage to zero volt and current to full rated value

(10.0 A)

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

[1]

or (4.0 A)

VOLT 0

CURR 10 (E3633A)

CURR 4 (E3634A)

[2]

by sending the commands:

Keysight E3633A and E3634A Service Guide 59

3 Calibration Procedures

4 Record the output voltage reading on the digital voltmeter (DVM). The reading

should be within the limit of (0 V ± 10 mV). Also, note that the CV, Adrs, Limit,
and Rmt annunciators are on.

5 Readback the output voltage over the remote interface by sending the

command:

MEAS:VOLT?

6 Record the value displayed on the controller. This value should be within the

limit of (DVM ±5 mV).

7 Program the output voltage to full rated value (20.0 V)

sending the command:

VOLT 20.0 (E3633A)

VOLT 50.0 (E3634A)

8 Record the output voltage reading on the digital voltmeter (DVM). The reading

should be within the limit of (20 V ± 20 mV)

9 Readback the output voltage over the remote interface by sending the

command:

[1]

or (50.0 V)

[1]

or (50 V ± 35 mV)

[2]

[2]

by

MEAS:VOLT?

10 Record the value displayed on the controller. This value should be within the

limit of (DVM ± 15 mV)

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

[1]

or (DVM ± 30 mV)

[2]

.

60 Keysight E3633A and E3634A Service Guide

CV load effect (load regulation)

This test measures the immediate change in the output voltage resulting from a
change in the output current from full to no load.

1 Turn off the power supply and connect a digital voltmeter between the (+) and

(-) terminals of the output as shown in Figure 3-1.

2 Turn on the power supply. Select the 20V/10A

output, and set the display to the limit mode. When the display is in the limit

mode, program the output current to the maximum programmable value and

the voltage to the full rated value (20.0 V)

3 Operate the electronic load in constant current mode and set its current to

[1]

(10.0 A)

or (4.0 A)

not lit, adjust the load so that the output current drops slightly until the CV

annunciator lights. Record the output voltage reading on the digital voltmeter.

4 Operate the electronic load in open mode (input off). Record the output

voltage reading on the digital voltmeter immediately. The difference between

the digital voltmeter readings in steps (3) and (4) is the CV load regulation. The

difference of the readings during the immediate change should be within the

limit of (4 mV)

[2]

[1]

or (7 mV)

. Check that the front panel CV annunciator remains lit. If

[2]

[1]

or 50V/4A

[1]

or (50.0 V)

Calibration Procedures 3

[2]

range, enable the

[2]

.

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

Keysight E3633A and E3634A Service Guide 61

3 Calibration Procedures

CV source effect (line regulation)

This test measures the immediate change in output voltage that results from a
change in ac line voltage from the minimum value (10% below the nominal input
voltage) to maximum value (10% above the nominal input voltage).

1 Turn off the power supply and connect a digital voltmeter between the (+) and

(-) terminals of the output to be tested as shown in Figure 3-1.

2 Connect the ac power line through a variable voltage transformer.

3 Turn on the power supply. Select the 20V/10A

the output, and set the display to the limit mode. When the display is in the
limit mode, program the current to the maximum programmable value and the

voltage to full rated value (20.0 V)

4 Operate the electronic load in constant current mode and set its current to

(10.0 A)
adjust the load so that the output current drops slightly until the CV
annunciator lights.

5 Adjust the transformer to low line voltage limit (104 Vac for nominal 115 Vac,

90 Vac for nominal 100 Vac, or 207 Vac for nominal 230 Vac). Record the
output reading on the digital voltmeter.

6 Adjust the transformer to high line voltage (127 Vac for nominal 115 Vac, 110

Vac for nominal 100 Vac, or 253 Vac for nominal 230 Vac). Record the voltage
reading on the digital voltmeter immediately. The difference between the
digital voltmeter readings in steps (5) and (6) is the CV line regulation. The
difference of the readings during the immediate change should be within the

limit of (4 mV)

[1]

or (4.0 A)

[2]

[1]

or (7 mV)

[1]

or (50.0 V)

[1]

or 50V/4A

[2]

.

[2]

range, enable

. Check that the CV annunciator remains lit. If not lit,

[2]

.

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

62 Keysight E3633A and E3634A Service Guide

CV PARD (ripple and noise)

Periodic and random deviations (PARD) in the output (ripple and noise) combine
to produce a residual ac voltage superimposed on the dc output voltage. CV
PARD is specified as the rms or peak-to-peak output voltage in the frequency
range from 20 Hz to 20 Mhz.

VRMS measurement techniques

When measuring Vrms ripple and noise, the monitoring device should be plugged
into the front of the terminals at (B) in Figure 3-2. Use the coaxial cable and BNC
female to banana plug adapter to connect the monitor device to the power
supply. To reduce the measurement error caused by common mode noise, it is
recommended that you use a common mode choke between the cable and the
BNC adapter. The common mode choke is constructed by inserting coaxial cable
into Ferrite Toroidal core. The load resistor should be connected to the terminal at
(A) in Figure 3-2. Twisted leads between the load resistor and the power supply
helps reduce noise pickup for these measurements.

1 Turn off the power supply and connect the output to be tested as shown in

Figure 3-1 to an oscilloscope (ac coupled) between (+) and (-) terminals. Set

the oscilloscope to AC mode and bandwidth limit to 20 MHz. Connect a

resistive load (2.0

2 Turn on the power supply. Select the 20V/10A

the output, and set the display to the limit mode. When the display is in the

limit mode, program the current to the full rated value (10.0 A)

and the voltage to the full rated value (20.0 V)

3 Check that the front panel CV annunciator remains lit. If not lit, adjust the load

down slightly.

[1]

Ω

)

or (12.5 Ω)

Calibration Procedures 3

[2]

to the terminal at (A) in Figure 3-2.

[1]

or 50V/4A

[1]

or (50.0 V)

[2]

range, enable

[1]

or (4.0 A)

[2]

.

[2]

4 Note that the waveform on the oscilloscope does not exceed the peak-to-peak

limit of 3 mV.

5 Disconnect the oscilloscope and connect the ac rms voltmeter in its place

according to the VRMS measurement techniques above. The rms voltage

reading does not exceed the rms limit of 0.35 mV

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

[1]

or 0.5 mV

[2]

.

Keysight E3633A and E3634A Service Guide 63

3 Calibration Procedures

Load transient response time

This test measures the time for the output voltage to recover to within 15 mV of
nominal output voltage following a load change from full load to half load, or half
load to full load.

1 Turn off the power supply and connect the output to be tested as shown in

Figure 3-1 with an oscilloscope. Operate the electronic load in constant

current mode.

2 Turn on the power supply. Select 20V/10A

output, and set the display to the limit mode. When the display is in the limit
mode, program the current to the full rated value (10.0 A)
the voltage to the full rated value (20.0 V)

3 Set the electronic load to transient operation mode between one half of the

output’s full rated value and the output’s full rated value at a 1 kHz rate with
50% duty cycle.

4 Set the oscilloscope for ac coupling, internal sync, and lock on either the

positive or negative load transient.

5 Adjust the oscilloscope to display transients as shown in Figure 3-3. Note that

the pulse width (t2 - t1) of the transients at 15 mV from the base line is no
more than 50 μsec for the output.

[1]

or 50V/4A

[1]

or (50.0 V)

[2]

range, enable the

[2]

[1]

.

or (4.0 A)

[2]

and

Figure 3-3 Transient response time

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

64 Keysight E3633A and E3634A Service Guide

Constant Current (CC) Verifications

Constant current test setup

Follow the general setup instructions in the Measurement Techniques and the
specific instructions will be given in the following paragraphs.

Current programming and readback accuracy

This test verifies that the current programming and GPIB or RS-232 readback
functions are within specifications. Note that the readback values over the remote
interface should be identical to those displayed on the front panel. The accuracy
of the current monitoring resistor must be 0.01% or better.

You should program the power supply over the remote interface for this test to
avoid round off errors.

1 Turn off the power supply and connect a 0.01 Ω current monitoring resistor

(R

) across the output to be tested and a digital voltmeter across the current

M

monitoring resistor (R

2 Turn on the power supply. Select the 8V/20A

the output by sending the commands:

).

M

Calibration Procedures 3

[1]

or 25V/7A

[2]

range and enable

VOLT:RANG P8V (E3633A)

VOLT:RANG P25V (E3634A)

OUTP ON

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

Keysight E3633A and E3634A Service Guide 65

3 Calibration Procedures

3 Program the output voltage to full rated voltage (8.0 V)

[1]

or (25.0 V)

[2]

and

output current to zero amps by sending the commands:

VOLT 8 (E3633A)

VOLT 25 (E3634A)

CURR 0

4 Divide the voltage drop (DVM reading) across the current monitoring resistor

(R

) by its resistance to convert to amps and record this value (IO). This value

M

should be within the limit of (0 A ± 10 mA). Also, note that the CC, Adrs, Limit,
and Rmt annunciators are on.

5 Readback the output current over the remote interface by sending the

command:

MEAS:CURR?

6 Record the value displayed on the controller. This value should be within the

limit of (I

7 Program the output current to the full rated value (20.0 A)

± 5 mA).

O

[1]

or (7.0 A)

[2]

by

sending the command:

CURR 20.0 (E3633A)

CURR 7.0 (E3634A)

8 Divide the voltage drop (DVM reading) across the current monitoring resistor

(RM) by its resistance to convert to amps and record this value (I

[1]

This value should be within the limit of (20 A ± 50 mA)

or (7A ± 24 mA)

).

O

[2]

.

9 Readback the output current over the remote interface by sending the

command:

MEAS:CURR?

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

66 Keysight E3633A and E3634A Service Guide

10 Record the value displayed on the controller. This value should be within the

limit of (I

± 35 mA)

O

[1]

or (IO ± 15.5 mA)

CC load effect (load regulation)

This test measures the immediate change in output current resulting from a
change in the load from full rated output voltage to short circuit.

1 Turn off the power supply and connect the output to be tested as shown in

Figure 3-1 with the digital voltmeter connected across the 0.01 Ω current

monitoring resistor (R

2 Turn on the power supply. Select the 8V/20A

output, and set the display to the limit mode. When the display is in the limit

mode, program the output voltage to the maximum programmable value and

the output current to the full rated value (20.0 A)

3 Set the voltage of the electronic load to (6.0 V)

constant voltage mode since a voltage drop occurs on the load wires when

[1]

(20.0 A)

or (7.0 A)
is on. If it is not, adjust the load so that the output voltage drops slightly.
Record the current reading by dividing the voltage reading on the digital
voltmeter by the resistance of the current monitoring resistor.

4 Operate the electronic load in short (input short) mode. Record the current

reading immediately by dividing the voltage reading on the digital voltmeter
by the resistance of the current monitoring resistor. The difference between
the current readings in step (3) and (4) is the load regulation current. The
difference of the readings during the immediate change should be within the

limit of (2.25 mA)

).

M

[2]

flows on the load wires. Check that the CC annunciator

[1]

or (0.95 mA)

[2]

Calibration Procedures 3

[2]

.

[1]

or 25V/7A

[1]

[1]

or (23.0 V)

[2]

or (7.0 A)

range, enable the

[2]

.

[2]

to operate it in

.

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

Keysight E3633A and E3634A Service Guide 67

3 Calibration Procedures

CC source effect (line regulation)

This test measures the immediate change in output current that results from a
change in ac line voltage from the minimum value (10% below the nominal input
voltage) to the maximum value (10% above nominal voltage).

1 Turn off the power supply and connect the output to be tested as shown in

Figure 3-1 with the digital voltmeter connected across the current monitoring

resistor (R

2 Connect the ac power line through a variable voltage transformer.

3 Turn on the power supply. Select the 8V/20A

output, and set the display to the limit mode. When the display is in the limit
mode, program the voltage to the full rated value (8.0 V)
the current to the full rated value (20.0 A)

4 Operate the electronic load in constant voltage mode and set its voltage to

(8.0 V)
adjust the load so that the output voltage drops slightly until the CC
annunciator lights.

5 Adjust the transformer to low line voltage limit (104 Vac for nominal 115 Vac,

90 Vac for nominal 100 Vac, or 207 Vac for nominal 230 Vac). Record the
output current reading by dividing the voltage reading on the digital voltmeter
by the resistance of the current monitoring resistor.

6 Adjust the transformer to 10% above the nominal line voltage (127 Vac for a

115 Vac nominal input, 110 Vac for a 100 Vac nominal input or 253 Vac for a
230 Vac nominal input). Record the current reading again immediately by
dividing the voltage reading on the digital voltmeter by the resistance of the
current monitoring resistor. The difference between the current readings in
step (5) and (6) is the load regulation current. The difference of the readings

during the immediate change should be within the limit of (2.25 mA)

[2]

mA)

).

M

[1]

or (25.0 V)

.

[1]

or 25V/7A

[1]

or (7.0 A)

[2]

. Check that the CC annunciator remains lit. If not lit,

[2]

range, enable the

[1]

or (25.0 V)

[2]

.

[1]

[2]

and

or (0.95

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

68 Keysight E3633A and E3634A Service Guide

CC PARD (ripple and noise)

Periodic and random deviations (PARD) in the output (ripple and noise) combine
to produce a residual ac current, as well as an ac voltage superimposed on the dc
output. CC PARD is specified as the rms output current in a frequency range 20 Hz
to 20 MHz with the power supply in constant current operation.

1 Turn off the power supply and connect the output to be tested as shown in

Figure 3-1with a load resistor (0.4 Ω)

Connect a rms voltmeter across the load resistor. Use only a resistive load for
this test.

2 Turn on the power supply. Select the 8V/20A

output, and set the display to the limit mode. When the display is in the limit
mode, program the current to full rated value (20.0 A)
voltage to the full rated value (8.0 V)

3 The output current should be at the full rated rating with the CC annunciator

on. If not lit, adjust the load so that the output voltage drops slightly until the

CC annunciator lights.

4 Divide the reading on the rms voltmeter by the load resistance to obtain rms

current. The readings should be within the limit of 2 mA.

[1]

or (3.5 Ω)

[1]

or (25.0 V)

Calibration Procedures 3

[2]

across output terminals.

[1]

or 25V/7A

[2]

[1]

or (7.0 A)

.

[2]

range, enable the

[2]

and the

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

Keysight E3633A and E3634A Service Guide 69

3 Calibration Procedures

Common Mode Current Noise

The common mode current is that ac current component which exists between
the output or output lines and chassis ground. Common mode noise can be a
problem for very sensitive circuitry that is referenced to earth ground. When a
circuit is referenced to earth ground, a low level line-related ac current will flow
from the output terminals to earth ground. Any impedance to earth ground will
create a voltage drop equal to the output current flow multiplied by the
impedance.

1 Turn off the power supply and connect a 100 kΩ resistor (R

capacitor in parallel between the (-) terminal and chassis ground.

2 Connect a digital voltmeter across R

3 Turn on the power supply. Select the 8V/20A

output, and set the display to the limit mode. When the display is in the limit
mode, program the output to the full rated value (8.0 V and 20.0 A)
V and 7.0 A)

4 Record the voltage across R

resistance (DVM reading/100 kΩ). Note that the current is less than 1.5 μA.

[2]

.

) and a 2200 pF

S

.

S

[1]

or 25V/7A

and convert it to current by dividing by the

S

[2]

range, enable the

[1]

or (25.0

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

70 Keysight E3633A and E3634A Service Guide

Calibration Procedures 3

Performance Test Record for Keysight E3633A and E3634A

CV performance test record

Test Description Models

CV Programming Accuracy @ 0 volts
(DVM reading)

CV Readback Accuracy @ 0 volts Both DVM + 0.0050 V DVM - 0.0050 V

CV Programming Accuracy
@ Full Scale (DVM reading)

CV Readback Accuracy @ Full Scale

CV Load Effect (Load Regulation)

CV Source Effect (Line Regulation)

CV PARD (Normal mode)

Load Transient Response Time Both

[a] For Keysight E3633A Model

[b] For Keysight E3634A Model

Both +0.0100 V -0.0100 V

(E3633A) +20.0200 V 19.9800 V

(E3634A) +50.0350 V 49.9650 V

(E3633A) DVM + 0.0150 V DVM - 0.0150 V

(E3634A) DVM + 0.0300 V DVM - 0.0300 V

Actual
Result

Upper Limit Lower Limit

Maximum change: < (4 mV)

Maximum change: < (4 mV)

< 3 mV p-p, (350

Specifications

[a]

μ

V)

or (500 μV)

< 50 μsec

[a]

or (7 mV)

[a]

or (7 mV)

[b]

[b]

[b]

rms

Keysight E3633A and E3634A Service Guide 71

3 Calibration Procedures

CC performance test records

Test Description Models

CC Programming Accuracy @ 0
amps (IO)

Both +0.0100 A -0.0100 A

CC Readback Accuracy @ 0 amps Both

CC Programming Accuracy @ Full
Scale (IO)

CV Readback Accuracy @ Full
Scale

(E3633A) 20.0500 A 19.9500 A

(E3634A) 7.0230 A 6.9770 A

(E3633A)

(E3634A)

CC Load Effect (Load Regulation)

CC Source Effect (Line Regulation)

Actual

Result

Upper Limit Lower Limit

I

O

IO + 0.0350 A IO - 0.0350 A

I

O

Maximum change: < (2.25 mA)

Maximum change: < (2.25 mA)

Specifications

+ 0.0050 A IO - 0.0050 A

+ 0.0155 A IO - 0.0155 A

CC PARD (Normal mode) Both < 2 mA rms

CC PARD (Common mode) Both

[a] For Keysight E3633A Model

[b] For Keysight E3634A Model

< 1.5

μ

A rms

[a]

or (0.95 mA)

[a]

or (0.95 mA)

[b]

[b]

72 Keysight E3633A and E3634A Service Guide

Calibration Security Code

NOTE

This feature allows you to enter a security code (electronic key) to prevent
accidental or unauthorized calibrations of the power supply. When you first
receive your power supply, it is secured. Before you can calibrate the power
supply, you must unsecure it by entering the correct security code. A procedure to
unsecure the power supply is given on the following page.

– The security code is set to “HP003633”

supply is shipped from the factory. The security code is stored in non-volatile
memory, and does not change when power has been off or after a remote
interface reset.

– To secure the power supply from the remote interface, the security code may

contain up to 12 alphanumeric characters as shown below. The first character
must be a letter, but the remaining characters can be letters or numbers. You
do not have to use all 12 characters but the first character must always be a
letter.

A _ _ _ _ _ _ _ _ _ _ _ (12 characters)

– To secure the power supply from the remote interface so that it can be

unsecured from the front panel, use the eight-character format shown below.
The first two characters must be “H P” and the remaining characters must be
numbers. Only the last six characters are recognized from the front panel, but
all eight characters are required. To unsecure the power supply from the front

panel, omit the “H P” and enter the remaining numbers as shown on the
following pages.

Calibration Procedures 3

[1]

or “HP003634”

[2]

when the power

H P _ _ _ _ _ _ (8 characters)

If you forget your security code, you can disable the security feature by adding a
jumper inside the power supply, and then entering a new code.

See“To unsecure the power supply without the security code” on page 76

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

Keysight E3633A and E3634A Service Guide 73

3 Calibration Procedures

To unsecure the power supply for calibration

The power supply can use a calibration security code to prevent unauthorized or
accidental calibration. This procedure shows you how to unsecure the power
supply for calibration from the front panel.

1 Turn on the front-panel calibration mode.

SECURED

Turn on the calibration mode by holding down (Calibrate) key as you turn
on the power supply and hold down the key until you hear a long beep.

If the power supply is secured, you will see the above message from the front
panel for approximately one second. The “CAL MODE” message is then
displayed on the front panel.

2 Move to the security code by pressing (Secure) key.

000000 CODE

3 Enter the security code using the knob and resolution selection keys.

003633 CODE (E3633A)

003634 CODE (E3634A)

The security code is set to “HP003633”

[1]

or “HP003634”

[2]

when the power
supply is shipped from the factory. The security code is stored in non-volatile
memory and does not change when the power has been off or after a remote
interface reset.

– To enter the security code from the front panel, enter only the last six

digits.

– To enter the security code from the remote interface, you may enter up to

12 characters.

[1] For Keysight E3633A Model

[2] For Keysight E3634A Model

74 Keysight E3633A and E3634A Service Guide

Calibration Procedures 3

NOTE

Use the resolution selection keys to move left or right between digits. Use the
knob to change the digits. Notice that the security code may be different if the
security code has been changed from the default setting.

4 Unsecure the power supply.

UNSECURED

The power supply is unsecured when you press (Secure) key. You will see
the above message from the front panel for one second. The “CAL MODE”
message is displayed on the front panel after above message.

5 Turn off the calibration mode.

Turn off the power supply to exit the calibration mode.

To re-secure the power supply (following calibration), perform this procedure
again.

Keysight E3633A and E3634A Service Guide 75

3 Calibration Procedures

To unsecure the power supply without the security code

To unsecure the power supply without the correct security code (when you forget
the security code), follow the steps below. See Electrostatic Discharge (ESD)

Precautions in chapter 5 before beginning this procedure.

1 Disconnect the power cord and all load connections from the power supply.

2 Remove the instrument cover.

3 Connect the power cord and turn on the calibration mode by holding down

(Calibrate) key as you turn on the power supply and hold down the key

until you hear a long beep. Be careful not to touch the power line connections.

4 Apply a short between the two exposed metal pads on JP5

U13). The JP5 is outlined with a circle on the“E3633-60002/E3634-60002

Component Locator for the Main Board” on page 125.

5 While maintaining the short, move to the security code and enter any unsecure

code in the calibration mode. The power supply is now unsecured.

6 Remove the short at JP5

7 Turn off and reassemble the power supply.

[2]

. (An error occurs if not removed.)

[1]

(located near

Now you can enter a new security code. Be sure you take note of the new
security code.

[1] For serial MY53xx6xxx, apply a short between the two exposed metal pads on JP102 (located near

U103). The JP102 is outlined with a circle on the component locator drawing on page 128

[2] For serial MY53xx6xxx, remove the short at JP102.

76 Keysight E3633A and E3634A Service Guide

Calibration Count

The calibration count feature provides an independent “serialization” of your
calibrations. You can determine the number of times that your power supply has
been calibrated. By monitoring the calibration count, you can determine whether
an unauthorized calibration has been performed. Since the value increments by
one for each calibration parameter (see Table 3-2 on the next page), a complete
calibration increases the value by 5 counts.

– The calibration count is stored in non-volatile memory and does not change

when power has been off or after a remote interface reset. Your power supply
was calibrated before it left the factory. When you receive the power supply,
read the calibration count to determine its value.

– The calibration count increments up to a maximum of 32,767 after which it

wraps around to 0. No way is provided to program or reset the calibration
count.

Calibration Procedures 3

Keysight E3633A and E3634A Service Guide 77

3 Calibration Procedures

Calibration Message

You can use the calibration message feature to record calibration information
about your power supply. For example, you can store such information as the last
calibration date, the next calibration due date, the power supply’s serial number,
or even the name and phone number of the person to contact for a new
calibration.

You can record and read information in the calibration message from the remote
interface only.

– The calibration message may contain up to 40 characters.

– The calibration message is stored in non-volatile memory and does not change

when power has been off or after a remote interface reset.

– Remote Interface Operation

CAL:SEC:STAT {OFF|ON},<code> Secure or unsecure the power supply

CAL:SEC:CODE <new code> Change the security code

CAL:STR <quoted string> Store the calibration message

CAL:STR? Query the calibration information

See “Calibration Overview”, starting on page 68 in chapter 3 of the User’s Guide
for more details.

78 Keysight E3633A and E3634A Service Guide

General Calibration/ Adjustment Procedure

NOTE

NOTE

The calibration procedures from the front panel are described in this section. For
voltage calibration, disconnect all loads from the power supply and connect a
DVM across the output terminals. For current calibration, disconnect all loads

from the power supply, connect an appropriate current monitoring resistor 0.01
across the output terminals, and connect a DVM across the terminals of the
monitoring resistor.

Note that the power supply should be calibrated after 1-hour warm-up with no
load connected.

The following table shows calibration parameters and points which should be
used to calibrate the output voltage and current.

Table 3-2 Parameters for calibration

Calibration Parameter Voltage/ Current Calibration Point Mnemonic

CAL SETUP 1 Voltage

Calibration Procedures 3

Ω

V LO

V MI

V HI

CAL SETUP 2 OVP None

I LO

CAL SETUP 3 Current

CAL SETUP 4 OCP None

You can terminate any CAL SETUP without changing its calibration constants by
turning off power.

Perform the voltage calibration prior to the OVP calibration and the current
calibration prior to the OCP calibration.

Keysight E3633A and E3634A Service Guide 79

I MI

I HI

3 Calibration Procedures

Front panel voltage and current calibration

1 Unsecure the power supply.

To calibrate the voltage and current, you must unsecure the power supply
according to the “To unsecure the power supply for calibration” on page 74.

2 Disconnect all loads from the power supply and connect a DVM across

output terminals.

3 Turn on calibration mode.

CAL MODE

Turn on the calibration mode by holding down (Calibrate) key as you turn
on the power supply and hold down the key until you hear a long beep. Make
sure that the power supply is in “CV” mode. If the power supply is not in “CV”
mode, an error occurs.

Voltage and OVP calibration

4 Move down a level to the voltage calibration mode.

CAL SETUP 1

The display shows the above message to indicate that the power supply is
ready for voltage calibration.

5 Calibrate DAC and select the low voltage calibration point.

30 LEFT

The “START BITCAL” message is displayed for about 3 seconds to indicate that
the power supply is ready for DAC calibration. Then it counts down numbers
from 30 to 0. Then, the display shows the low voltage calibration point.

V LO 0.5000V

80 Keysight E3633A and E3634A Service Guide

Calibration Procedures 3

6 Read the DVM and change the low voltage value on the d isplay to match

the measured voltage.

For example, if the DVM reading is 0.4500 V, adjust the voltage to 0.4500 V
using the knob and resolution selection keys.

V LO 0.4500 V

7 Pressing (Calibrate) key saves the change and selects the middle

voltage calibration point. (“V MI 25.000 V” - E3634A model)

V MI 10.000 V (E3633A)

If the entered number is within an acceptable range, an “ENTERED” message
appears for one second. If the entered number is not correct, an “MIN VALUE”
or “MAX VALUE” message appears for one second and the display shows the
low voltage calibration point again. The display now shows the middle voltage
calibration point.

8 Read the DVM and change the middle voltage value on the d isplay to match

the measured voltage.

For example, if the DVM reads 10.001 V, adjust the voltage to 10.001 V using
the knob and arrow keys.

V MI 10.001 V

9 Pressing (Calibrate) key saves the changes and selects the high

voltage calibration point. (“V HI 49.500 V” - E3634A model)

V HI 19.500 V (E3633A)

If the entered number is within an acceptable range, an “ENTERED” message
appears for one second. If the entered number is not correct, an “MIN VALUE”
or “MAX VALUE” message appears for one second and the display shows the
middle voltage calibration point again. The display now shows the high
voltage calibration point.

Keysight E3633A and E3634A Service Guide 81

3 Calibration Procedures

NOTE

10 Read the DVM and change the high voltage value on the d isplay to match

the measured voltage.

For example, if the DVM reads 19.495 V, adjust the voltage to 19.495 V using
the knob and arrow keys.

V HI 19.495 V

11 Pressing (Calibrate) key saves the new voltage calibration constants,

and goes to the OVP calibration mode.

CAL SETUP 2

A “CALIBRATING” message appears for one second to indicate that the
voltage calibration is progressing and new voltage calibration constants of
“SETUP 1” are stored. Then, the display shows above message to indicate that
the power supply is ready for the OVP calibration.

If the calibration fails, a “DAC CAL FAIL” or “ADC CAL FAIL” message appears
for one second and the display shows the “CAL SETUP 1” for voltage
calibration again.

Current and OCP calibration

12 Pressing (Calibrate) key saves the new calibration constants for OVP

circuit and goes to the current calibration mode.

CAL SETUP 3

A “CALIBRATING” message appears for about several seconds to indicate that
the OVP calibration is progressing and new calibration constants of “SETUP 2”
are stored. Then, the display shows the above message to indicate that the
power supply is ready for the current calibration.

If the calibration fails, a “OVP CAL FAIL” message appears for one second and
the display shows the “CAL SETUP 2” for OVP calibration again.

Connect an appropriate shunt 0.01 Ω across the output terminals, and connect a
digital voltmeter across the shunt resistor for the current calibration.

82 Keysight E3633A and E3634A Service Guide

Calibration Procedures 3

13 Select the low current calibration point. (‘‘I LO 0.2000 A’’ - E3634A model)

I LO 0.5000 A (E3633A)

The display shows the low current calibration point.

14 Read the DVM and change the low current value on the display to match

the computed current (DVM reading ÷ by shunt resistance).

For example, if the computed value is 0.4990 A, adjust the current to 0.4990 A
using the knob and arrow keys.

Notice that you should wait for the DVM reading to stabilize for accurate
calibration.

I LO 0.4990 A

15 Pressing the “Calibrate” key saves the change and selects the middle

current calibration point. (“I MI 3.5000 A’’ - E3634A model)

I MI 10.000 A (E3633A)

If the entered number is within an acceptable range, an “ENTERED” message
appears for one second. If the entered number is not correct, an “MIN VALUE”
or “MAX VALUE” message appears for one second and the display shows the
low current calibration point again. The display now shows the middle current
calibration point.

16 Read the DVM and change the middle current value on the display to match

the computed current (DVM reading ÷ by shunt resistance).

For example, if the computed value is 9.999 A, adjust the current to 9.999 A
using the knob and arrow keys.

Notice that you should wait for the DVM reading to stabilize for accurate
calibration.

I MI 09.999 A

Keysight E3633A and E3634A Service Guide 83

3 Calibration Procedures

17 Pressing the “Calibrate” key saves the change and selects the high current

calibration point. (“I HI 6.9000 A” - E3634A model)

I HI 19.500 A (E3633A)

If the entered number is within an acceptable range, an “ENTERED” message
appears for one second. If the entered number is not correct, an “MIN VALUE”
or “MAX VALUE” message appears for one second and the display shows the
middle current calibration point again. The display now shows the high current
calibration point.

18 Read the DVM and change the high current value on the d isplay to match

the computed current (DVM reading ¸ by shunt resistance).

For example, if the computed value is 19.499 A, adjust the current to 19.499 A
using the knob and arrow keys.

Notice that you should wait for the DVM reading to stabilize for accurate
calibration.

I HI 19.499 A

19 Pressing the ‘‘Calibrate’’ key saves the new calibration constants for the

output current and goes to the OCP calibration mode.

CAL SETUP 4

A “CALIBRATING” message appears for one second to indicate that the current
calibration is progressing and new calibration constants of “SETUP 3” are
stored. Then, the display shows the above message to indicate that the power
supply is ready for the OCP calibration.

If the calibration fails, an “DAC CAL FAIL” or “ADC CAL FAIL” message appears
for one second and the display shows the “CAL SETUP 3” for current
calibration again.

84 Keysight E3633A and E3634A Service Guide

20 Pressing the “Calibrate” key saves the new OCP calibration constants and

return to the calibration mode.

CAL MODE

A “CALIBRATING” message appears for several seconds to indicate that the
OCP calibration is progressing and new OCP calibration constants of “SETUP
4” are stored. Then the display will return to the calibration mode.

If the calibration fails, a “OCP CAL FAIL” message appears for one second and
the display shows the “CAL SETUP 4” for OCP calibration again.

Turn off the power supply to exit the calibration mode.

Aborting a Calibration in Progress

Sometimes it may be necessary to abort a calibration after the procedure has
already been initiated. You can abort a calibration at any time by turning the
power supply off from the front panel. When performing a calibration from the
remote interface, you can abort a calibration by issuing a remote interface device
clear message or by pressing the front-panel “Local” key.

Calibration Procedures 3

Keysight E3633A and E3634A Service Guide 85

3 Calibration Procedures

Calibration Record for Keysight E3633A/E3634A

Step Calibration Description

Measurement

Mode (DVM)

Supply Being

Adjusted

1 Unsecure the power supply (see page 62).

2 Turn on “CAL MODE” (hold down “Calibrate” and “Power” keys as you turn on the

power supply until you hear a long beep).

3 Move down menu to “CAL SETUP 1” (press “Calibrate” key). Voltage

Calibration

4 Calibrate DAC and select the low point for voltage calibration; “START BITCAL”

appears for about 3 seconds and the display counts down numbers from 30 to 0.
Then, “V LO 0.5000 V” appears on the display (press “Calibrate” key and wait

VDAC and low

voltage point
calibration

about 30 seconds; then change the display to match the DVM reading).

5

“V MI 10.000 V”

[a]

or “V MI 25.000 V”

(press “Calibrate” key; then change the display to match the DVM reading).

6

“V HI 19.500 V”

[a]

or “V HI 49.500 V”

(press “Calibrate” key; then change the display to match the DVM reading).

[b]

appears on the display

[b]

appears on the display

VMiddle voltage

point calibration

V High vol tage point

calibration

7 “CAL SETUP 2” now appears on the display (press “Calibrate” key). V OVP calibration

8 “CAL SETUP 3” now appears on the display

(press “Calibrate” key; then connect 0.01

9

“I LO 0.5000 A”

[a]

or “I LO 0.2000 A”

Ω

resistor across the output terminals).

[b]

appears on the display

(press “Calibrate” key; then change the display to match the computed current

A Low current point

Current
calibration

calibration

through the resistor).

10

“I MI 10.000 A”

[a]

or “I MI 3.5000 A”

(press “Calibrate” key; then change the display to match the computed current

[b]

appears on the display

A Middle current

point calibration

through the resistor).

11

“I HI 19.500 A”

[a]

or “I HI 6.9000 A”

(press “Calibrate” key; then change the display to match the computed current

[b]

appears on the display

A High current point

calibration

through the resistor).

12 “CAL SETUP 4” now appears on the display (press “Calibrate” key). A OCP calibration

13 Press “Calibrate” key, then press “Power” switch. Exit CAL MODE

[a] For Keysight E3633A Model

[b] For Keysight E3634A Model

86 Keysight E3633A and E3634A Service Guide

Error Messages

The following tables are abbreviated lists of error messages for the E3633A and
E3634A. The errors listed are the most likely errors to be encountered during
calibration and adjustment. A more complete list of error messages and
descriptions is contained in chapter 5 of the E3633A and E3634A User’s Guide.

System error messages

Error Error Messages

-330 Self-test failed

-350 Queue overflow

501 Isolator UART framing error

502 Isolator UART overrun error

503

511 RS-232 framing error

512 RS-232 overrun error

513 RS-232 parity error

514 Command allowed only with RS-232

521 Input buffer overflow

522 Output buffer overflow

550 Command not allowed in local

Calibration Procedures 3

[a]

SPI data error

[a] This error message is only applicable for serial MY53xx6xxx.

Keysight E3633A and E3634A Service Guide 87

3 Calibration Procedures

Self-test error messages

Error Error Messages

601 Front panel does not respond

602 RAM read/write failed

603 A/D sync stuck

604 A/D slope convergence failed

605 Cannot calibrate rundown gain

606 Rundown gain out of range

607 Rundown too noisy

608 Serial configuration readback failed

[a]

609

624 Unable to sense line frequency

625 I/O processor does not respond

626 I/O processor failed self-test

630 Fan test failed

631 System DAC test failed

632 Hardware test failed

System ADC test failed

[a] This error message is only applicable for serial MY53xx6xxx.

88 Keysight E3633A and E3634A Service Guide

Calibration error messages

Error Error Messages

701 Cal security disabled by jumper

702 Cal secured

703 Invalid secure code

704 Secure code too long

705 Cal aborted

708 Cal output disabled

712 Bad DAC cal data

713 Bad readback cal data

714 Bad OVP cal data

715 Bad OCP cal data

716 Bad DAC DNL error correction data

717 Cal OVP or OCP status enabled

718 Gain out of range for gain error correction

740 Cal checksum failed, secure state

741 Cal checksum failed, string data

742 Cal checksum failed, store/recall data in location 0

743 Cal checksum failed, store/recall data in location 1

744 Cal checksum failed, store/recall data in location 2

745 Cal checksum failed, store/recall data in location 3

746 Cal checksum failed, DAC cal constants

747 Cal checksum failed, readback cal constants

748 Cal checksum failed, GPIB address

749 Cal checksum failed, internal data

750 Cal checksum failed, DAC DNL error correction data

Calibration Procedures 3

Keysight E3633A and E3634A Service Guide 89

3 Calibration Procedures

An Example Program of Excel 97 for Calibration

This section contains an Excel Macros (Visual Basic® for Applications) program
for calibration over the GPIB interface. This program makes software adjustments
to the E3633A power supply using a current shunt and a digital multimeter which
is connected to the controller. In this program a 0.001 ohm current shunt is used.
Be sure to change the value of the variable “shunt” to the value of the current
shunt used and the GPIB address for the power supply and the digital voltmeter.

'**********************************************************************
' This program was written on a PC with Excel Macros (Visual Basic® for
' Applications) for Windows 95 or Windows NT 4.0. It will make software
' adjustments to the E3633A Power Supply on the GPIB bus using a
' Keysight 34401A Digital Multimeter and a current shunt. In the program
' a 0.001 ohm current shunt is used to measure current. Be sure to
' change the value of the variable ‘shunt’ to the value of the current
' shunt used.
'**********************************************************************

Global id_power As Long
Global id_DMM As Long
Global power As Long
Global DMM As Long
Global Const VI_SUCCESS = &H0&
Global Const VoltageMin = 0
Global Const VoltageMid = 1
Global Const VoltageMax = 2
Global Const CurrentMin = 3
Global Const CurrentMid = 4
Global Const CurrentMax = 5

Sub Calibration_Click()Max

Dim shunt As Single 'Current shunt value in Ohms
Dim UserAnswer 'User response
Range("B4:B6").ClearContents

If OpenPort = False Then

ClosePort

Exit Sub
End If
InitializeDevice
EnableOVPandOCP False
If CheckSecurity = False Then

ClosePort

Exit Sub
End If

Continued on next page

90 Keysight E3633A and E3634A Service Guide

Calibration Procedures 3

If DacErrorCorrection = False Then

ClosePort
Exit Sub

End If

shunt = 0.001 'Change the current shunt value

UserAnswer = MsgBox(“Voltage & OVP calibration. Connect the output to the

DMM”, vbYesNo + vbQuestion, “E3633A Calibration”)

If UserAnswer = vbNo Then

ClosePort
Exit Sub

End If

Range("B4").Select
ActiveCell.Value = "Begin Voltage Calibration"
StartCalibration VoltageMin, True, shunt 'Set output to minimum voltage cal
ActiveCell.Value = "End Minimum Voltage Calibration"
StartCalibration VoltageMid, True, shunt 'Set output to middle voltage cal
ActiveCell.Value = "End Middle Voltage Calibration"
StartCalibration VoltageMax, True, shunt 'Set output to maximum voltage cal
ActiveCell.Value = "End Maximum Voltage Calibration"
Message = SendSCPI(power, "Syst:Err?")
If InStr(Message, "0") Then

ActiveCell.Value = "Voltage Calibration Complete"

Else

ActiveCell.Value = Message
ClosePort
Exit Sub

End If

OVPandOCPCalibration True

UserAnswer = MsgBox("Connect the Current shunt to the DMM input to
measure a current. Connect the output to the shunt.",
vbYesNo + vbQuestion, "E3633A Calibration")

If UserAnswer = vbNo Then

ClosePort
Exit Sub

End If

ActiveCell.Value = "Begin Current Calibration"
StartCalibration CurrentMin, False, shunt 'Set output to minimum current

cal

ActiveCell.Value = "End Minimum Current Calibration"
StartCalibration CurrentMid, False, shunt 'Set output to middle current cal
ActiveCell.Value = "End Middle Current Calibration"
StartCalibration CurrentMax, False, shunt 'Set output to maximum current

cal

ActiveCell.Value = "End Maximum Current Calibration"

Continued on next page

Keysight E3633A and E3634A Service Guide 91

3 Calibration Procedures

OVPandOCPCalibration False
Message = SendSCPI(power, "Syst:Err?")
If InStr(Message, "0") Then

Else

End If
EnableOVPandOCP True
SaveDate
ActiveCell.Value = "Calibration Complete"
Message = SendSCPI(power, "*RST")
ClosePort

End Sub

Private Function OpenPort() As Boolean 'Open communications on GPIB

Dim Power_Address As String
Dim DMM_Address As String
Dim Error As Long

Power_Address = "5" 'Select power supply GPIB address between 0 to 30
DMM_Address = "22" 'Select DMM GPIB address between 0 to 30
Error = viOpenDefaultRM(id_power) 'Open the power supply VISA session
If OpenPort = CheckError(Error, "Open ID Error to Power Supply") Then

End If
Error = viOpenDefaultRM(id_DMM) 'Open the DMM VISA session
If OpenPort = CheckError(Error, "Open ID Error to Digital Multi Meter")

Then

End If
Error = viOpen(id_power, "GPIB0::" & Power_Address & "::INSTR", 0, 1000,

power)

If OpenPort = CheckError(Error, "Unable Open to Power Supply") Then

End If
Error = viOpen(id_DMM, "GPIB0::" & DMM_Address & "::INSTR", 0, 1000, DMM)
If OpenPort = CheckError(Error, "Unable Open to Digital Multi Meter") Then

End If
OpenPort = True

End Function

ActiveCell.Value = "Current Calibration Complete"

ActiveCell.Value = Message

ClosePort

Exit Sub

Exit Function

Exit Function

Exit Function

Exit Function

Private Function InitializeDevice()

SendSCPI power, "*Cls"
SendSCPI DMM, "*Rst" 'Set power-on condition for DMM
SendSCPI power, "*Rst" 'Set power-on condition for power supply

End Function

Continued on next page

92 Keysight E3633A and E3634A Service Guide

Calibration Procedures 3

Private Function CheckError(Error As Long, Message As String) As Boolean

If Error < VI_SUCCESS Then

ActiveCell.Value = Message
CheckError = False 'Exit Calibration

Else

CheckError = True

End Function

Private Function ClosePort()

End Function

Private Function EnableOVPandOCP(bEnable As Boolean)

End Function

'This routine send a SCPI command string to the GPIB port.
'If the command contains a question mark, the response is read, and returned

Private Function SendSCPI(device As Long, command As String) As String

End Function

Private Function delay(delay_time As Single)
'This routine is used to create delays

End Function

End If

Dim Error As Long
Error = viClose(power)
Error = viClose(id_power)
Error = viClose(DMM)
Error = viClose(id_DMM)

If bEnable Then

SendSCPI power, "Volt:Prot:Stat On"
SendSCPI power, "Curr:Prot:Stat On"

Else

SendSCPI power, "Volt:Prot:Stat Off"
SendSCPI power, "Curr:Prot:Stat Off"

End If

Dim commandString As String
Dim ReturnString As String
Dim crlfpos As Integer
Dim ReadBuffer As String * 512
Dim actual As Long
Dim Error As Long
commandString = command & Chr$(10)

Error = viWrite(device, ByVal commandString, Len(commandString), actual)
If InStr(commandString, "?") Then

Error = viRead(device, ByVal ReadBuffer, 512, actual)
ReturnString = ReadBuffer
crlfpos = InStr(ReturnString, Chr$(0))
If crlfpos Then

ReturnString = Left(ReturnString, crlfpos - 2)
End If
SendSCPI = ReturnString

End If

Dim Finish As Single
Finish = Timer + delay_time
Do
Loop Until Finish <= Timer

Continued on next page

Keysight E3633A and E3634A Service Guide 93

3 Calibration Procedures

Private Function CheckSecurity() As Boolean

Dim Message As String
Dim SecurityCode As String
Message = SendSCPI(power, "Cal:Str?")
Range("B5").Select
ActiveCell.Value = Message
Message = SendSCPI(power, "Cal:Count?")
Range("B6").Select
ActiveCell.Value = Message
Range("B4").Select
SecurityCode = "HP003633"
SendSCPI power, "Cal:Sec:Stat Off," & SecurityCode
Message = SendSCPI(power, "Cal:Sec:Stat?")

If InStr(Message, "1") Then

Else

Else

End If

End If

End Function

Private Function DacErrorCorrection() As Boolean

Dim Message As String
SendSCPI power, "Output On" 'Turn on the power supply output
SendSCPI power, "Cal:Dac:Error"
For I = 1 To 27

Next I
SendSCPI power, "Output Off" 'Turn off the power supply output
Message = SendSCPI(power, "Syst:Err?")
If InStr(Message, "0") Then

Else

End If

End Function

ActiveCell.Value = "Unable to Unsecure the Power Supply"
CheckSecurity = False

Message = SendSCPI(power, "Syst:Err?")
If InStr(Message, "0") Then

CheckSecurity = True

ActiveCell.Value = Message
CheckSecurity = False

delay 1
ActiveCell.Value = "Waitting for " & Str$(27 - I) & "secs"

ActiveCell.Value = "DAC DNL Error Correction completed for power
supply"
DacErrorCorrection = True

ActiveCell.Value = Message
DacErrorCorrection = False

Continued on next page

94 Keysight E3633A and E3634A Service Guide

Calibration Procedures 3

Private Function StartCalibration(mode As Integer, bVolt As Boolean, shunt As
Single)

Dim DMMdata As Single

SendSCPI power, "Output On" 'Turn on the power supply outpu
Select Case mode

Case VoltageMin

SendSCPI power, "Cal:Volt:Level Min" 'Set output to minimum cal

value
Case VoltageMid

SendSCPI power, "Cal:Volt:Level Mid" 'Set output to middle cal

value
Case VoltageMax

SendSCPI power, "Cal:Volt:Level Max" 'Set output to maximum cal

value
Case CurrentMin

SendSCPI power, "Cal:Curr:Level Min" 'Set output to minimum cal

value
Case CurrentMid

SendSCPI power, "Cal:Curr:Level Mid" 'Set output to middle cal

value
Case CurrentMax

SendSCPI power, "Cal:Curr:Level Max" 'Set output to maximum cal

End Select

delay 4
DMMdata = SendSCPI(DMM, "Meas:Volt:DC?") 'measure output

If bVolt Then

Else

End If
SendSCPI power, "Output Off" 'Turn off the power supply output

End Function

Private Function OVPandOCPCalibration(bVolt As Boolean)

SendSCPI power, "Output On" 'Turn on the power supply output
If bVolt Then

Else

End If
delay 9
SendSCPI power, "Output Off" 'Turn off the power supply output

End Function

value

'Send the measured voltage value to the power supply

SendSCPI power, "Cal:Volt:Data " & Str(DMMdata)

'Send the measured current value to the power supply
SendSCPI power, "Cal:Curr:Data " & Str(DMMdata / shunt)

ActiveCell.Value = " Begin OVP Calibration"
SendSCPI power, "Cal:Volt:Prot" 'Perform OVP circuit calibration

ActiveCell.Value = " Begin OCP Calibration"
SendSCPI power, "Cal:Curr:Prot" 'Perform OCP circuit calibration

Continued on the next page

Keysight E3633A and E3634A Service Guide 95

3 Calibration Procedures

Private Function SaveDate()

Dim Message As String
'calibration string enclosed in quotes
Message = "Cal:Str " & Chr(34) & Date & Chr(34)
SendSCPI power, Message
Message = SendSCPI(power, "Cal:Str?")
Range("B5").Select
ActiveCell.Value = Message
Message = SendSCPI(power, "Cal:Count?")
Range("B6").Select
ActiveCell.Value = Message

Range("B4").Select

End Function

End of program

96 Keysight E3633A and E3634A Service Guide

Calibration Procedures 3

Declaration for Windows 95/NT 4.0

Declare Function viOpenDefaultRM Lib "visa32.dll" (instrumentHandle As Long) As
Long

Declare Function viOpen Lib "visa32.dll" (ByVal instrumentHandle As Long, _

ByVal viDesc As String, ByVal mode As Long, ByVal timeout As Long, _
vi As Long) As Long

Declare Function viClose Lib "visa32.dll" (ByVal vi As Long) As Long

Declare Function viWrite Lib "visa32.dll" (ByVal vi As Long, ByVal Buffer As
String, ByVal count As Long, retCount As Long) As Long

Declare Function viRead Lib "visa32.dll" (ByVal vi As Long, ByVal Buffer As
String, _ByVal count As Long, retCount As Long) As Long

Keysight E3633A and E3634A Service Guide 97

3 Calibration Procedures

THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK.

98 Keysight E3633A and E3634A Service Guide

Keysight E3633A and E3634A DC Power Supplies
Service Guide

4 Theory of Operation

Block Diagram Overview 100
AC Input and Bias Supplies 102
Floating Logic 103
D-to-A Converter 105
A-to-D Converter 106
Power Mesh and Control 107
Earth-Referenced Logic 108
Front Panel 109

This chapter provides block diagram level descriptions of the power supply. The
descriptions provide a basic understanding of circuit operation and are intended
as an aid in troubleshooting. It is assumed in the following discussions that you
are familiar with the operating and programming instructions presented in the
E3633A and E3634A User’s Guide. Subjects covered include the following:

99

4 Theory of Operation

Block Diagram Overview

This discussion pertains to the block diagram on the next page. The power
supply’s circuitry is divided into two major blocks: the floating circuitry and the
earth referenced circuitry. All power mesh and control circuits, display circuit, and
digital circuits are contained in the floating circuitry. This circuitry also contains
the power supply’s main controller. The earth referenced circuitry provides the
interface between the user and the power supply.

The floating circuitry can be viewed in four pieces; the DAC system, the digital
logic section (floating logic), the power mesh and control section, and the front
panel (display and keyboard) section.

The floating logic receives digital signals from the earth-referenced logic and the
DAC converts them to analog signals which are sent to the power control circuits
in order to program the power supply’s output voltage and current. The power
supply can also be commanded to send measurement and status data back to the
remote interface controller and/or the VFD (vacuum fluorescent display) display
on the front panel. The data is processed and sent back via the floating logic and
earth-referenced logic.

The power mesh and control circuits contains voltage and current control circuits
which allows the power supply to operate in either the constant voltage (CV) or
constant current (CC) mode. The control circuits compare the power supply’s
output voltage or current with the programmed value and generates a control
signal which varies the conduction of the series pass transistor to raise or lower
the output as required.

The front panel circuits consist of VFD control, display high voltage drivers, and
keyboard scanning. Communication between the front panel and floating logic
circuits is accomplished through a 4-wire bi-directional serial interface.

The earth referenced circuitry uses a controller configured as a slave to the main
controller. This controller establishes external I/O communication with the main
controller through a bi-directional, optically isolated, serial communications link.
The earth referenced controller controls low-level GPIB (IEEE-488) and RS-232
interface operation.

Separate reference and bias supplies are provided for the floating and ground
reference circuitry. The front panel operates from the floating circuitry with its
logic common different from the main controller logic common.

100 Keysight E3633A and E3634A Service Guide