Tektronix DG2020A User manual

Service Manual
DG2020A
Data Generator
071-0055-52
Warning
The servicing instructions are for use by qualified
personnel only. To avoid personal injury, do not
perform any servicing unless you are qualified to
do so. Refer to all safety summaries prior to
performing service.
www.tektronix.com

Copyright ©Tektronix, Inc. All rights reserved.
Tektronix products are covered by U.S. and foreign patents, issued and pending. Information in this publication supercedes
that in all previously published material. Specifications and price change privileges reserved.
Tektronix, Inc., P.O. Box 500, Beaverton, OR 97077
TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.
Contacting Tektronix
Tektronix, Inc.
14200 SW Karl Braun Drive
P.O. Box 500
Beaverton, OR 97077
USA
For product information, sales, service, and technical support:
HIn North America, call 1--800--833--9200.
HWorldwide, visit www.tektronix.com to find contacts in your area.In North America, call 1--800--833--9200.

WARRANTY
Tektronix warrants that this product will be free from defects in materials and workmanship for a period of one (1) year
from the date of shipment. If any such product proves defective during this warranty period, Tektronix, at its option, either
will repair the defective product without charge for parts and labor, or will provide a replacement in exchange for the
defective product.
In order to obtain service under this warranty, Customer must notify Tektronix of the defect before the expiration of the
warranty period and make suitable arrangements for the performance of service. Customer shall be responsible for
packaging and shipping the defective product to the service center designated by Tektronix, with shipping charges prepaid.
Tektronix shall pay for the return of the product to Customer if the shipment is to a location within the country in which the
Tektronix service center is located. Customer shall be responsible for paying all shipping charges, duties, taxes, and any
other charges for products returned to any other locations.
This warranty shall not apply to any defect, failure or damage caused by improper use or improper or inadequate
maintenance and care. Tektronix shall not be obligated to furnish service under this warranty a) to repair damage resulting
from attempts by personnel other than Tektronix representatives to install, repair or service the product; b) to repair
damage resulting from improper use or connection to incompatible equipment; or c) to service a product that has been
modified or integrated with other products when the effect of such modification or integration increases the time or
difficulty of servicing the product.
THIS WARRANTY IS GIVEN BY TEKTRONIX WITH RESPECT TO THIS PRODUCT IN LIEU OF ANY
OTHER WARRANTIES, EXPRESSED OR IMPLIED. TEKTRONIX AND ITS VENDORS DISCLAIM ANY
IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
TEKTRONIX’ RESPONSIBILITY TO REPAIR OR REPLACE DEFECTIVE PRODUCTS IS THE SOLE AND
EXCLUSIVE REMEDY PROVIDED TO THE CUSTOMER FOR BREACH OF THIS WARRANTY. TEKTRONIX
AND ITS VENDORS WILL NOT BE LIABLE FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR
CONSEQUENTIAL DAMAGES IRRESPECTIVE OF WHETHER TEKTRONIX OR THE VENDOR HAS
ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.

DG2020A Service Manual i
Table of Contents
General Safety Summary vii...................................
Service Safety Summary ix....................................
Preface xi...................................................
Introduction xiii..............................................
Specifications
Product Description 1-1........................................
Features 1-1........................................................
Performance Characteristics 1-3................................
Warranted Characteristics 1-4..........................................
Typical Characteristics 1-9............................................
Nominal Traits 1-11..................................................
Certification and Compiances 1-16......................................
Operating Information
Preparation for Use 2-1........................................
Supplying Power 2-1.................................................
Power Cord Information 2-2...........................................
Operating Environment 2-3...........................................
Rear Panel Controls 2-3..............................................
Fuse Type and Rating 2-4.............................................
Applying and Interrupting Power 2-5....................................
Repackaging Instructions 2-6..........................................
Installed Options 2-6.................................................
Operating Instructions 2-7.....................................
How to Make Connection to Pods 2-7...................................
How to Power On 2-9................................................
Internal Diagnostics Routines 2-9......................................
User Interface 2-9...................................................
Display 2-11........................................................
Menus 2-13.........................................................
Pattern Storage and I/O 2-13...........................................
Loading Files 2-14...................................................
Signal Output 2-15...................................................
Theory of Operation
Theory of Operation 3-1.......................................
Module Overview 3-1................................................
Options 3-3........................................................
Performance Verification
Performance Verification 4-1...................................
Introduction 4-1....................................................

Table of Contents
ii DG2020A Service Manual
Before Running the Operation Tests 4-2.................................
Test Procedure Notes 4-4.............................................
Self Tests 4-5.......................................................
Performance Tests for the DG2020A/Pod Combination 4-6..................
P3410 Pod Performance Test 4-17.......................................
P3420 Pod Performance Test 4-24.......................................
Adjustment Procedure
Adjustment Procedures 5-1.....................................
Maintenance
Maintenance 6-1..............................................
Preparation 6-1.....................................................
Inspection and Cleaning 6-4...........................................
Removal and Installation Procedures 6-9.........................
Preparation 6-9.....................................................
Access Procedure 6-12................................................
Procedures for External Modules 6-15....................................
Procedures for Internal Modules 6-26....................................
Repackaging 6-45..............................................
Repackaging Instructions 6-45..........................................
Troubleshooting 6-47...........................................
Troubleshooting Procedures 6-47........................................
DG2020A Diagnostics 6-47............................................
Options
Options and Accessories 7-1....................................
Options A1--A5 7-1..................................................
Option 01 Description 7-2............................................
Option 02 Description 7-2............................................
Option 1R Description 7-2............................................
Option 95 Description 7-2............................................
P3410 Option 95 Description 7-3.......................................
P3420 Option 95 Description 7-3.......................................
Accessories 7-4.....................................................
Electrical Parts List
Electrical Parts List 8-1........................................
Diagrams
Diagrams 9-1.................................................
Mechanical Parts List
Replaceable Mechanical Parts 10-1...............................
Parts Ordering Information 10-1.........................................
Using the Replaceable Parts List 10-2....................................

Table of Contents
DG2020A Service Manual iii
List of Figures
Figure 1-1: Trigger delay 1-7....................................
Figure 2-1: Rear panel controls 2-4..............................
Figure 2-2: Pod connection 2-7..................................
Figure 2-3: Yellow index mark and yellow wire for cable connection 2-8
Figure 2-4: CRT display 2-11....................................
Figure 2-5: Load data & setup menu 2-14..........................
Figure 2-6: Operating buttons and menu layout 2-15................
Figure 2-7: Pod channel data bit allocation 2-19....................
Figure 2-8: Output voltage level and delay time display
for the P3420 pod 2-21......................................
Figure 4-1: Operating buttons and menu layout 4-4................
Figure 4-2: Diagnostics menu 4-5................................
Figure 4-3: Frequency measurement connections 4-6...............
Figure 4-4: External clock input connection 4-8....................
Figure 4-5: Pod connection 4-10..................................
Figure 4-6: P3410 data output connectors 4-11......................
Figure 4-7: P3420 data output connectors 4-11......................
Figure 4-8: External trigger operation connections 4-13..............
Figure 4-9: P3410 event input connections 4-15.....................
Figure 4-10: P3420 event input connections 4-15....................
Figure 4-11: DG2020A event output connections 4-16................
Figure 4-12: Pod connection 4-17.................................
Figure 4-13: P3410 voltage level display 4-18.......................
Figure 4-14: P3410 output pins 4-18..............................
Figure 4-15: Pin header cable types 4-18...........................
Figure 4-16: Output voltage test connections 4-19...................
Figure 4-17: Variable delay test connections 4-20....................
Figure 4-18: Event input operation confirmation connections 4-22.....
Figure 4-19: Inhibit operation confirmation connections 4-23.........
Figure 4-20: Pod connection 4-24.................................
Figure 4-21: P3420 voltage level display 4-25.......................
Figure 4-22: P3420 output connectors 4-25.........................
Figure 4-23: Output voltage level measurement connections 4-26......
Figure 4-24: Variable delay precision check 4-29....................
Figure 4-25: Event input operation confirmation connections 4-31.....

Table of Contents
iv DG2020A Service Manual
Figure 4-26: Inhibit input operation confirmation connections 4-32....
Figure 6-1: DG2020A orientation 6-11.............................
Figure 6-2: Guide to removal procedures 6-12......................
Figure 6-3: External modules 6-13...............................
Figure 6-4: Internal modules 6-14................................
Figure 6-5: Front-panel knob removal 6-16........................
Figure 6-6: Line fuse and line cord removal 6-17....................
Figure 6-7: Rear cover and cabinet removal 6-19....................
Figure 6-8: Front cover, trim ring, and menu button removal
(front cover not shown) 6-21..................................
Figure 6-9: Front-panel module removal 6-23......................
Figure 6-10: A12 keyboard removal 6-24...........................
Figure 6-11: Disassembly of front-panel module 6-25................
Figure 6-12: Connector module removal 6-28.......................
Figure 6-13: Fan and fan frame removal 6-29.......................
Figure 6-14: Rear shield cover removal 6-30........................
Figure 6-15: Power supply module removal 6-31....................
Figure 6-16: AUX power board and AC inlet removal 6-33...........
Figure 6-17: Monitor module removal 6-35.........................
Figure 6-18: CRT frame removal 6-36.............................
Figure 6-19: Circuit boards removal 6-39..........................
Figure 6-20: A17 backplane board removal 6-41....................
Figure 6-21: Battery location on the A17 backplane board 6-43.......
Figure 6-22: Floppy-disk drive module removal 6-44................
Figure 6-23: A6 CPU board 6-48.................................
Figure 6-24: Primary troubleshooting procedure--(1) 6-49............
Figure 6-25: Primary troubleshooting procedure--(2) 6-50............
Figure 6-26: POD connector troubleshooting procedure 6-51..........
Figure 6-27: Troubleshooting procedure 1 — power supply module 6-52
Figure 6-28: AUX power board 6-53..............................
Figure 6-29: Power supply module 6-53...........................
Figure 6-30: Troubleshooting procedure 2 —
A6 CPU board or front-panel module 6-54.....................
Figure 6-31: Key board 6-55.....................................
Figure 6-32: Troubleshooting procedure 3 — monitor module 6-56....
Figure 6-33: Monitor module 6-57................................
Figure 6-34: Horizontal and vertical sync signals 6-57...............
Figure 6-35: A video signal with white and black levels 6-58..........
Figure 6-36: Troubleshooting procedure 4 — module Isolation 6-59...

Table of Contents
DG2020A Service Manual v
Figure 9-1: Block diagram of DG2020A with options 01 and 02 9--3...
Figure 9-2: Interconnect diagram of DG2020A
with options 01 and 02 9--4..................................
Figure 10-1: Cabinet 10-5.......................................
Figure 10-2: Main chassis and CRT 10-7...........................
Figure 10-3: Main chassis and circuit boards 10-9...................
Figure 10-4: Circuit boards 10-11.................................
Figure 10-5: Front panel assembly 10-13............................
Figure 10-6: Option 01 10-14.....................................
Figure 10-7: Option 02 10-15.....................................

Table of Contents
vi DG2020A Service Manual
List of Tables
Table 1-1: Warranted electrical characteristics 1-4.................
Table 1-2: Warranted environmental characteristics 1-8............
Table 1-3: Electrical characteristics (typical) 1-9...................
Table 1-4: Nominal traits -- electrical characteristics 1-11............
Table 1-5: Nominal traits -- mechanical characteristics 1-15..........
Table 1-6: Certifications and compliances 1-16.....................
Table 2-1: Power-cord conductor identification 2-2................
Table 2-2: Power cord identification 2-2..........................
Table 2-3: Fuse type and rating 2-4..............................
Table 2-4: DG2030 display elements 2-12..........................
Table 4-1: Performance check disk’s file list 4-2...................
Table 4-2: Required equipment 4-3..............................
Table 4-3: Error Codes 4-5.....................................
Table 4-4: Internal clock frequency precision (PLL off) 4-8..........
Table 4-5: Delay precision 4-21..................................
Table 4-6: High level output voltage ranges for a 1 MW load 4-27.....
Table 4-7: Low level output voltage ranges for a 1 MW load 4-28.....
Table 4-8: Delay precision 4-30..................................
Table 6-1: Relative susceptibility to static-discharge damage 6-3.....
Table 6-2: External inspection check list 6-5......................
Table 6-3: Internal inspection check list 6-6.......................
Table 6-4: Equipment required 6-10..............................
Table 7-1: International power cords 7-1.........................
Table 7-2: Standard accessories 7-4.............................
Table 7-3: Standard accessories for pods 7-4......................
Table 7-4: Optional accessories 7-5..............................
Table 7-5: Maintenance kit contents 7-6..........................

DG2020A Service Manual vii
General Safety Summary
Review the following safety precautions to avoid injury and prevent damage to
this product or any products connected to it. To avoid potential hazards, use this
product only as specified.
Only qualified personnel should perform service procedures.
Use Proper Power Cord. Use only the power cord specified for this product and
certified for the country of use.
Connect and Disconnect Properly. Do not connect or disconnect probes or test
leads while they are connected to a voltage source.
Ground the Product. This product is grounded through the grounding conductor
of the power cord. To avoid electric shock, the grounding conductor must be
connected to earth ground. Before making connections to the input or output
terminals of the product, ensure that the product is properly grounded.
Observe All Terminal Ratings. To avoid fire or shock hazard, observe all ratings
and markings on the product. Consult the product manual for further ratings
information before making connections to the product.
Do Not Operate Without Covers. Do not operate this product with covers or panels
removed.
Use Proper Fuse. Use only the fuse type and rating specified for this product.
Avoid Exposed Circuitry. Do not touch exposed connections and components
when power is present.
Do Not Operate With Suspected Failures. If you suspect there is damage to this
product, have it inspected by qualified service personnel.
Do Not Operate in Wet/Damp Conditions.
Do Not Operate in an Explosive Atmosphere.
Keep Product Surfaces Clean and Dry.
Provide Proper Ventilation. Refer to the manual’s installation instructions for
details on installing the product so it has proper ventilation.
To Avoid Fire or
Personal Injury

General Safety Summary
viii DG2020A Service Manual
Terms in this Manual. These terms may appear in this manual:
WAR NING . Warning statements identify conditions or practices that could result
in injury or loss of life.
CAUTION. Caution statements identify conditions or practices that could result in
damage to this product or other property.
Terms on the Product. These terms may appear on the product:
DANGER indicates an injury hazard immediately accessible as you read the
marking.
WARNING indicates an injury hazard not immediately accessible as you read the
marking.
CAUTION indicates a hazard to property including the product.
Symbols on the Product. The following symbols may appear on the product:
Protective Ground
(Earth) Terminal
CAUTION
Refer to Manual
Double
Insulated
WARNING
High Voltage
Symbols and Terms

DG2020A Service Manual ix
Service Safety Summary
Only qualified personnel should perform service procedures. Read this Service
Safety Summary and the General Safety Summary before performing any service
procedures.
Do Not Service Alone. Do not perform internal service or adjustments of this
product unless another person capable of rendering first aid and resuscitation is
present.
Disconnect Power. To avoid electric shock, disconnect the mains power by means
of the power cord or, if provided, the power switch.
Use Caution When Servicing the CRT. To avoid electric shock or injury, use
extreme caution when handling the CRT. Only qualified personnel familiar with
CRT servicing procedures and precautions should remove or install the CRT.
CRTs retain hazardous voltages for long periods of time after power is turned off.
Before attempting any servicing, discharge the CRT by shorting the anode to
chassis ground. When discharging the CRT, connect the discharge path to ground
and then the anode. Rough handling may cause the CRT to implode. Do not nick
or scratch the glass or subject it to undue pressure when removing or installing it.
When handling the CRT, wear safety goggles and heavy gloves for protection.
Use Care When Servicing With Power On. Dangerous voltages or currents may
exist in this product. Disconnect power, remove battery (if applicable), and
disconnect test leads before removing protective panels, soldering, or replacing
components.
To avoid electric shock, do not touch exposed connections.
X-Radiation. To avoid x-radiation exposure, do not modify or otherwise alter the
high-voltage circuitry or the CRT enclosure. X-ray emissions generated within
this product have been sufficiently shielded.

Service Safety Summary
xDG2020A Service Manual

DG2020A Service Manual xi
Preface
This is the service manual for the DG2020A Data Generator. The manual
contains information needed to service the DG2020A to the module level.
Manual Structure
This manual is divided into sections, such as Specifications and Theory of
Operation. Further, some sections are divided into subsections, such as Product
Description and Removal and Installation Procedures.
Sections containing procedures also contain introductions to those procedures.
Be sure to read these introductions because they provide information needed to
do the service correctly and efficiently. The following contains a brief description
of each manual section.
HSpecifications contains a description of the DG2020A and the characteristics
that apply to it.
HOperating Information includes general information and operating instruc-
tions at the level needed to safely power on and service the DG2020A.
HTheory of Operation contains circuit descriptions that support general service
to the module level.
HPerformance Verification contains a collection of procedures for confirming
that the DG2020A functions properly and meets warranted limits.
HAdjustment Procedures contains a statement explaining that adjustment is
unnecessary for the DG2020A.
HMaintenance contains information and procedures for performing preventive
and corrective maintenance of the DG2020A. These instructions include
cleaning, module removal and installation, and fault isolation to the module.
HOptions contains information on servicing any of the factory-installed
options that your DG2020A includes.
HElectrical Parts List contains a statement referring you to Mechanical Parts
List, where both electrical and mechanical modules are listed. See below.
HDiagrams contains block diagrams and an interconnection diagram useful in
isolating failed modules.
HMechanical Parts List includes a table of all replaceable modules, their
descriptions, and their Tektronix part numbers.

Preface
xii DG2020A Service Manual
Manual Conventions
This manual uses certain conventions that you should become familiar with.
Some sections of the manual contain procedures for you to perform. To keep
those instructions clear and consistent, this manual uses the following
conventions:
HNames of front panel controls and menus appear in the same case (initial
capitals, all uppercase, etc.) in the manual as is used on the DG2020A front
panel and menus. Front panel names are all upper-case letters; for example,
SETUP MENU, HARDCOPY,etc.
HInstruction steps are numbered unless there is only one step.
Throughout this manual, any replaceable component, assembly, or part of the
DG2020A is referred to generically as a module. In general, a module is an
assembly (like a circuit board), rather than a component (like a resistor or an
integrated circuit). Sometimes a single component is a module; for example, the
chassis of the DG2020A is a module.
Symbols and terms related to safety appear in the Safety Summary near the
beginning of this manual.
Finding Other Information
Other documentation for the DG2020A Data Generator includes:
HThe DG2020A User Manual contains a tutorial to quickly describe how to
operate the DG2020A. It also includes an in-depth discussion on how to
more completely use DG2020A features.
HThe DG2020A Programmer Manual explains how to control the DG2020A
with a computer through the GPIB or RS-232-C interface.
Modules
Safety

DG2020A Service Manual xiii
Introduction
This manual contains information needed to properly service the DG2020A Data
Generator, as well as general information critical to safe and effective servicing.
To prevent personal injury or damage to the DG2020A, consider the following
before attempting service:
HThe procedures in this manual should be performed only by a qualified
service person
HRead the General Safety Summary and the Service Safety Summary,
beginning on page vii near the beginning of this manual
HRead Preparation for Use in section 2, Operating Information
When using this manual for servicing, be sure to follow all warnings, cautions,
and notes.
Performance Check Interval
Generally, the performance check described in section 4, Performance Verifica-
tion, should be done every 12 months. In addition, performance check is
recommended after module replacement.
If the DG2020A does not meet performance criteria, repair is necessary.
Strategy for Servicing
Throughout this manual, the term, module, refers to any field-replaceable
component, assembly, or part of the DG2020A.
This manual contains all the information needed for periodic maintenance of the
DG2020A. (Examples of such information are procedures for checking perfor-
mance.)
Further, it contains all information for corrective maintenance down to the
module level. To isolate a failure to a module, use the fault isolation procedures
found in Troubleshooting, part of section 6, Maintenance. To remove and replace
any failed module, follow the instructions in Removal and Installation Proce-
dures, also part of section 6. After isolating a faulty module, replace it with a
fully-tested module obtained from the factory. Section 10, Mechanical Parts
List, contains part number and ordering information for all replaceable modules.

Introduction
xiv DG2020A Service Manual
Tektronix Service Offerings
Tektronix provides service to cover repair under warranty as well as other
services that may provide a cost-effective answer to your service needs.
Whether providing warranty repair service or any of the other services listed
below, Tektronix service technicians are well equipped to service the DG2020A.
Tektronix technicians train on Tektronix products; they have access to the latest
information on improvements to the DG2020A as well as the latest new options.
Tektronix warrants this product for one year from date of purchase. (The
warranty appears on the back of the title page in this manual.) Tektronix
technicians provide warranty service at most Tektronix service locations
worldwide. The Tektronix product catalog lists all service locations worldwide.
Tektronix supports repair to the module level by providing Module Exchange.
Module Exchange. This service reduces down-time for repair by allowing you to
exchange most modules for remanufactured ones. Tektronix ships an updated and
tested exchange module from the Beaverton, Oregon service center, typically
within 24 hours. Each module comes with a 90-day service warranty.
For More Information. Contact your local Tektronix service center or sales
engineer for more information on any of the repair or adjustment services just
described.
Warranty Repair Service
Self Service

DG2020A Service Manual 1-1
Product Description
The DG2020A is a digital data generator designed for high performance and ease
of use. The DG2020A is easy to use for testing and evaluating semiconductors
and logic circuits, which are continually becoming faster and more complex.
The DG2020A provides, in a compact package, high performance and a wide
range of functions. Features include a maximum data rate of 200 MHz, a 64K
word pattern memory, 12 channels (with support for up to 36 channels by adding
optional modules), a 100 ps timing skew adjustment function, and variable
output levels (from --3 to +7V).
Any memory size from 64 words to 64K words can be used easily, with no
restrictions within that range. TTL output level and variable output level pods
can be selected as the data output pods. Both pod types support setting of their
output stages to a high-impedance state. Each module supports delays in 4 of its
12 channels with a 100-ps-resolution variable delay time.
The DG2020A provides flexible data editing functions, including word and line
unit input and extended data creation functions. Furthermore, the DG2020A
provides a rich set of functions required for system construction, such as a
sequencing function, a jump function using external input, and an inhibit
function.
Features
HThe DG2020A supports smooth and rapid product development by
simulating the digital signals from incomplete sections of a product.
HLogic function test systems can be constructed by combining this instrument
with a logic analyzer.
HMargin tests can be easily performed by using this instrument to generate
patterns that have a low probability of occurrence or are difficult to generate.
This can increase end-product reliability.
HInteractive digital simulation systems can be constructed using the sequence
output, external jump, and tristate control functions.
HFlexible data output functions make the DG2020A an ideal data generator
for simulation of LCD display units, CCD line and area sensors, and all
types of digital circuits.

Product Description
1-2 DG2020A Service Manual