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.
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, ei ther
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 suita ble arrangements for the performance of service. Customer shall be responsible for
packaging and shipping the defective product to the service center de signated by Tektronix, with shipping charges prepaid.
Tektronix shall pay for the re turn of the product to Customer if the shipment is to a location within the country in which the
Tektronix service center i s located. Customer shall be responsible for paying a ll 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 W ARRANTIES, EXPRESSED OR IMPLIED. TEKTRONIX AND ITS VENDORS DISCLAIM ANY
IMPLIED W ARRANTIES OF MERCHANT ABILITY 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.
Table of Contents
Specifications
Operating Information
General Safety Summaryvii...................................
Service Safety Summaryix....................................
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.
To Avoid Fire or
Personal Injury
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.
DG2020A Service Manual
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.
vii
General Safety Summary
Symbols and Terms
Terms in this Manual. These terms may appear in this manual:
WARNING. 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:
WARNING
High Voltage
Protective Ground
(Earth) Terminal
CAUTION
Refer to Manual
Double
Insulated
viii
DG2020A Service Manual
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.
DG2020A Service Manual
ix
Service Safety Summary
x
DG2020A Service Manual
Preface
Manual Structure
This is the service manual for the DG2020A Data Generator. The manual
contains information needed to service the DG2020A to the module level.
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 i ntroductions 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 t he 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.
DG2020A Service Manual
xi
Preface
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 t he 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.
Modules
Safety
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
HThe DG2020A Programmer Manual explains how to control the DG2020A
operate the DG2020A. It also includes an in-depth discussion on how to
more completely use DG2020A features.
with a computer through the GPIB or RS-232-C interface.
xii
DG2020A Service Manual
Introduction
This manual contains information needed to properly service the DG2020A Data
Generator, as well as general i nformation 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 Verification, should be done every 12 m onths. In addition, performance check is
recommended after module replacement.
Strategy for Servicing
If the DG2020A does not meet performance criteria, repair is necessary.
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 performance.)
Further, it contains all information for corrective maintenance down to the
module level. To isolate a failure to a module, use t he 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 PartsList, contains part number and ordering information for all replaceable modules.
DG2020A Service Manual
xiii
Introduction
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.
Warranty Repair Service
Self Service
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.
xiv
DG2020A Service Manual
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.
DG2020A Service Manual
1-1
Product Description
1-2
DG2020A Service Manual
Performance Characteristics
The performance characteristics on the DG2020A can be divided into three
categories:
HNominal Traits. General characteristics are described not by equipment
performance and limits but by such things as memory capacity.
HWarranted Characteristics. Warranted characteristics are described in terms of
quantifiable performance limits which are guaranteed.
HTypical Characteristics. Typical characteristics are described in terms of
typical or average performance for the DG2020A. The characteristics
described herein are not absolutely guaranteed.
Items marked with * are tested in the Performance Verification (Section 4).
The certification and compliances for the DG2020A are also found at the end of
this appendix.
DG2020A Service Manual
1-3
Performance Characteristics
k
f
pag
page4-1
9
Warranted Characteristics
This section will describe the warranted characteristics of the DG2020A. These
can be divided into two main categories: electrical characteristics and environmental characteristics.
Performance Conditions
The electrical characteristics are valid under the following conditions:
1. The instrument must be in an environment whose limits are described in
Environmental Characteristics.
2. All tolerance limits apply after a 20 minute warm up.
3. The instrument is operating at an ambient temperature between +10 _Cto
+40 _C, unless otherwise noted.
Items marked with * are tested in the Performance Verification (Appendix B)
Table 1 -1: Warranted electrical characteristics
CharacteristicsDescriptionPerformance
T est
Clock generator
*Internal clockCheck internal
cloc
Frequency accuracy
PLL on¦50 ppm (0.005%)
PLL off¦3%
P3410 ( TTL output pod )
requency,
page 4-6.
Data outputCheck output
*Output voltage
V
OH
V
OL
Rise / fall time< 5 ns ( 20% to 80%, into 1 MΩ 10 pF )
Maximum operating temperature decreases 1_C each 300 m above
1.5 km.
Non operatingTo 15 km (50,000 feet).
Dynamics
Vibration
Operating0.33 mm
Shock
Non operating294 m/s2(30 G), half-sine, 11 ms duration.
Installation requirements
Power consumption
(Fully loaded)
Surge current30 A peak for < 5 line cycles, after product has been off for at least 30 s.
Cooling clearance
Top clearance1 inch
Side clearance6 inches
Rear clearance3 inches
300 watts max. Maximum line current is 4 A rms at 50 Hz, 90 V line.
, 10 to 55 Hz, 15 minutes
p-p
1-8
DG2020A Service Manual
Typical Characteristics
This section will describe the typical characteristics for the DG2020A. These
values represent typical or average performance and are not absolutely guaranteed.
Table 1 -3: Electrical characteristics (typical)
CharacteristicsDescription
Clock generator
Internal clock
Period jitterMeasured by TDS694C--1MHD with TDSJIT1
RefertoTable1-4.
Cycle to cycle jitterMeasured by TDS694C--1MHD with TDSJIT1
RefertoTable1-5.
P3410 ( TTL output pod )
Performance Characteristics
Data output
Over / under shoot< 0.5V(into1MΩ 10 pF )
Rise / fall time2 ns ( 20% to 80%, into 1 MΩ 10 pF )
Channel skew< 3 ns ( CH0 and other channels, same pod )
< 2 ns ( CH0 and CH0, two pods of same type )
Internal inhibit delay-- 5 n s
Inhibit input
Delay to data output18 ns
P3420 ( Variable output pod )
Data output
Output currentTotal output current < 500 mA
< --30 mA ( Sink )
> +30 mA ( Source )
Over / under shoot< ¦(5%ofSwing)¦ 0.1V(into1MΩ 10 pF )
Rise / fall time2 ns ( 20% to 80%, into 1 MΩ 10pF,0to5Vswing)
Channel skew< 3 ns ( CH0 and other channels, same pod )
Period jitterMeasured by TDS694C--1MHD with TDSJIT1
RefertoTable1-4.
Cycle to cycle jitterMeasured by TDS694C--1MHD with TDSJIT1
RefertoTable1-5.
Auxiliary outputs
Sync output
Duration6 clocks ( Tw1in Figure 1-1 )
Clock output
Delay to data output24 ns ( P3410 )
20 ns ( P3420 )
Auxiliary inputs
External clock input
Delay to P3410 data output36 ns
Delay to P3420 data output33 ns
Table 1-4: Period JItter
Clock frequency200 MHz (When PLL to On.)100 MHz (When PLL to On.)
MeasurementStdDevPk--PkStdDevPk--Pk
Clock output13.0 ps70.0 ps10.0 ps60.0 ps
Data output (CH0 output)6.0 ps35.0 ps5.5 ps34.0 ps
Table 1 -5: Cycle to Cycle JItter
Clock frequency200 MHz (When PLL to On.)100 MHz (When PLL to On.)
MeasurementStdDevPk--PkStdDevPk--Pk
Clock output20.0 ps115.0 ps17.0 ps110.0 ps
Data output (CH0 output)9.0 ps52.0 ps8.5 ps50.0 ps
1-10
DG2020A Service Manual
Nominal Traits
This section describes general characteristics of the DG2020A. These can be
divided into two main categories: electrical characteristics and mechanical
characteristics.