Tektronix 2232 User manual

I-
T C I/ SERVICE 070-7067-00
Product Grow 41
2232
DIGITAL STORAGE
OSCILLOSCOPE
SERVICE
&IALIFIED’ TO DO so. REFER TO OPERATORS
THE FOLLOWING SERVICING INSTRUCTIONS ARE
FOR USE BY QUALIFIED PERSONNEL ONLY. TO
AVOID PERSONAL INJURY, DO NOT PERFORM ANY
I SERVICING OTHER THAN THAT CONTAINED IN
OPERATING INSTRUCTIONS UNLESS YOU ARE
SAFETY SUMMARY AN0 SERVICE SAFETY SUM- I
MARY PRIOR TO PERFORMING ANY SERVICE.
Please Check for
CHANGE INFORMATION
at the Rear of This Manual
First Printing OEC 1989
Revised APR 1990

SPECIFICATION
INTRODUCTION ............. l-l
ACCURACY ANW
RESOLUTION ................ 1-l
STANDARD ACCESSORIES .... l-2
PERFORMANCE
CONDITIONS ................ l-2
OPERATING INFORMATION
SAFETY ..................... 2-1
LINE VOLTAGE ............... 2-l
POWER CORD ............... 2-l
LINE FUSE .................. 2-l
INSTRUMENT COOLING ....... 2-2
START-UP .................. 2-2
REPACKAGING .............. 2-2
THEORY OF OPERATION
SECTION ORGANIZATION ..... 3-1
INTEGRATED CIRCUIT
DESCRIPTIONS .............. 3-1
GENERAL DESCRIPTION ...... 3-1
DETAILED CIRCUIT
DESCRIPTION ................. 3-7
INTRODUCTION ............. 3-7
VERTICAL ATTENUATORS ..... 3-7
VERTICAL PREAMPLIFIERS .... 3-9
VERTICAL OUTPUT
AMPLIFIER ................. 3-12
TRIGGERING ............... 3-13
A SWEEP GENERATOR AND
LOGIC ..................... 3-17
B TIMING AND ALTERNATE
B SWEEP .................. 3-20
HORIZONTAL ............... 3-24
MICROPROCESSOR ......... 3-26
STATUS ADC AND BUS
INTERFACE ................ 3-29
2232 Service
TABLE OF CONTENTS
Page Page
LIST OF ILLUSTRATIONS . . . . . . . . . . _. . . . a. Ill
LIST OF TABLES . . . . . . . . . . . . . . . . . . . . . . . . . Y
OPERATORS SAFETY SUMMARY *. _. . . . . . . . vl
SERVICING SAFETY SUMMARY . . . . . . . . . . . . . VII
Section I
STORAGE ACQUISITION ..... 3-29
DIGITAL TIME BASE ......... 3-30
DIGITAL DISPLAY ............ 3-31
VECTOR GENERATOR ....... 3-33
DIGITAL ACQUISITION AND
MEMORY .................. 3-34
POWER INPUT, PREREGULATOR
AND INVERTER ............. 3-35
POWER SUPPLY SECONDARIES,
Z-AXIS AND CRT ............ 3-38
X-Y PLOTTER .............. 3-41
Sectlon 4 PERFORMANCE CHECK
PROCEDURE
INTRODUCTION ............... 4-l
PURPOSE .................. 4-l
PERFORMANCE CHECK
INTERVAL ................... 4-l
STRUCTURE ................ 4-l
TEST EQUIPMENT
REQUIRED .................. 4-l
LIMITS AND TOLERANCES ..... 4-l
PREPARATION FOR CHECKS ... 4-1
INDEX TO PERFORMANCE
CHECK STEPS ............... 4-3
VERTICAL ...................... 4-4
INITIAL CONTROL
SEITINGS .................. 4-4
PROCEDURE STEPS .......... 4-4
HORIZONTAL ................. 4-l 1
INITIAL CONTROL
SETTINGS ................. 4-I 1
PROCEDURE STEPS ......... 4-l 1
TRIGGER .................... 4-16
INITIAL CONTROL
SElTlNGS ................. 4-1 B
PROCEDURE STEPS ......... 4-16
DCTERNAL Z-AXIS. PROBE ADJUST,
EXTERNAL CLOCK, AND X-Y
PLOTTER .................... 4-20
INITIAL CONTROL
SETRNGS ................. 4-20
PROCEWURE STEPS ......... 4-20
I

2232 Service
Section 5 AVJUSTMENT PROCl3XIRE
INTRODUCTION ............... 5-1
PURPOSE .................. 5-l
STRUCTURE ................ 5-1
TEST EQUIPMENT
REQUIRED .................. 5-l
LIMITS AND TOLERANCES ..... 5-l
ADJUSTMENTS AFFECTED
BY REPAIRS ................. 5-l
PREPARATION FOR
ADJUSTMENT ............... 6-2
INDEX TO ADJUSTMENT
PROCEDURE STEPS .......... 5-3
POWER SUPPLY AND CRT
DISPLAY ...................... 5-4
INITIAL CONTROL
SETTINGS .................. 5-4
PROCEDURE STEPS .......... 5-4
VERTICAL ..................... 5-6
INITIAL CONTROL
SEITINGS .................. 5-6
PROCEDURE STEPS .......... 6-6
HORIZONTAL ................. 5-15
INITIAL CONTROL
SEITINGS ................. 5-15
PROCEDURE STEPS ......... 5-15
TRIGGER .................... 5-21
INITIAL CONTROL
SEITINGS ................. 5-21
PROCEDURE STEPS ......... 5-21
SeCtIon 6 MAINTENANCE
STATIC-SENSITIVE
COMPONENTS . 6-l
PREVENTIVE MAINTENANCE 6-2
INTRODUCTION . t 6-2
GENERAL CARE . . t , . 6-2
INSPECTION AND CLEANING 6-2
LUBRICATION 6-4
SEMICONDUCTOR CHECKS 6-4
PERIODIC READJUSTMENT.. 6-4
TROUBLESHOOTING . 6-4
INTRODUCTION . . 6-4
TROUBLESHOOTING AIDS . 6-4
TROUBLESHOOTING
EQUIPMENT.. . , *. 6-10
-
DIAGNOSTICS .............. 6-15
CORRECTIVE MAINTENANCE ... 6-21 I
INTRODUCTION ............ 6-21
MAINTENANCE
PRECAUTIONS ............. 6-21 II
OBTAINING REPLACEMENT
PARTS ..................... 6-21’
MAINTENANCE AIDS ........ 6-21
INTERCONNECTIONS. I ....... 6-23
LITHIUM BAlTERY (BTI 101) ... 6-23
TRANSISTORS AND
INTEGRATED CIRCUITS ...... 6-23
SOLDERING TECHNIQUES ... 6-23
REMOVAL AND REPLACEMENT
INSTRUCTIONS ............. 6-25
Sectlon 7 OPTIONS
INTRODUCTION ............... 7-l
OPTIONS DESCRIPTION ........ 7-1
INTERNATIONAL POWER CORD I
OPTIONS ................... 7-1
OPTION 10 .................. 7-1
OPTION 12 .................. 7-1
OPTION 33 .................. 7-l
SERVICING INFORMATION,, 7-l
OPTION 10 THEORY OF
OPERATION ................. 7-l
OPTION 12 THEORY OF
OPERATION ................. 7-3 I
PERFORMANCE CHECK
PROCEDURE ................ 7-4
ADJUSTMENT PROCEDURE ... 7-6
OPTION MAINTENANCE
INFORMATION t 7-6
Sectlon 9 REPLACEABLE ELECTRICAL PARTS I
Sectlon 9 DIAGRAMS I
Section 10 REPLACEABLE MECHANICAL PARTS
CHANGE INFORMATION

2232 Servlce
LIST OF ILLUSTRATIONS
3-l
3-2
3-3
3-4
3-5
37-6
3-7
3-8
3-9
6-1
6-2
6-3
6-4
6-5
6-6
6-7
9-l
9-2
9-3
9-4
9-5
9-6
9-7
9-8
9-9
9-10
9-11
9-12
9-13
9-14
9-15
9-16
9-17
The2232Oscilloscope ...............................................
Maximum Input voltage versus frequency derating curve for the CW 1 OR X.
CH2ORY,andEXflNPUTconnectors ..................................
Physical dimensions of the 2232 Oscilloscope ............................
Securing the detachable power cord to the instrument ......................
Optional power cords. ................................................
Simplified block diagram ..............................................
Block diagram of the Channel 1 Attenuator circuit ..........................
Store/Non-Store Vertical Switching ......................................
Block Diagram of the Trigger Amplifiers and Switching ......................
A Sweep Generator and Logic circuitry ..................................
B Sweep Generator and Logic clrcultty ..................................
Horizontal Amplifier block diagram ......................................
Power Supply block dlagram ...........................................
Simplified diagram of the DC Restorer circuitry ............................
Multi-connector holder orientation ......................................
GroundingthesignallinesofP2111andP211.2 ...........................
Isolated Kernel timing .................................................
DiagnosticMenu Map ................................................
Location of screws and spacers on the Storage circuit board ................
Recessed screw and rear hinge removal .................................
Location of screws securing Power Supply shield and the support bracket to the
rearchassisframe ...................................................
Color codes for resistors and capacitors
Semiconductor lead configuratlons
Locating COmpoflents on schematic diagrams and circuit board illustrations
Detailed analog block diagram
Detailed storage block diagram
A2-Attenuator board
A14-CH 1 Logic board
A15-CH 2 Logic board
Al -Main board
Circuit View of Al -Main board
Al A8 - CH 1 Bandwidth Limit board
Al A9 - CH 2 Bandwidth Limit board
A3 - Front Panel board
Circuit view of A3 - Front Panel board
A4-Timing board
Al 3 -Sweep Interface board
A5-Alternate Sweep board
Page
VIII
I-17
1-18
2-l
2-2
-. 3-2
3-8
3-l 1
3-14
3-18
3-21
3-25
3-36
3-40
6-7
6-7
6-6
6-16
6-27
6-28
6-30

9-19 AB-EMI Fil;er board
9-20 AlAlE-Thermal Shutdown board
O-21 A31 -Scale lllum board
Q-22 AIO-Storage board
9-23 A20-XY Plotter board
O-24 A21 - RS-232 Option board
9-25 A22-GPIB Option board
O-26 Al -Main board adjustment looations
9-27 A2-Attenuator board adjustment locations
O-28 A4-Timing board adlustmont locations
9-29 AS-Ah Sweep Logic board adjustment locations
9-30 Al 6-Sweep Reference board adjustment locations
Q-31 AIO-Storage board adjustment locations

Table
l-l
1-2
l-3
3-l
4-l
4-2
4-3
4-4
4-5
4-6
4-7
5-l
5-2
5-3
5-4
8-5
5-6
5-7
5-8
6-1
6-2
6-3
B-4A
6-48
6-5
B-6
6-7
6-8
6-Q
6-10
6-11
6-12
6-13
7-1
7-2
7-3
2232 Service
LIST OF TABLES
Page
Electrical Characteristics ................................................... i-3
Environmental Characteristics .............................................. 1-15
Physical Characteristics ................................................... i-17
Memory Space Allocation ................................................. 3-28
Test Equipment Required ................................................... 4-2
Deflection Accuracy Limits ................................................. 4-4
Storage Deflection Accuracy ................................................ 4-5
Settings for Bandwidth Checks .............................................. 4-7
Settings for Timing Accuracy Checks ........................................ 4-12
Settings for Delay Time Differential Checks ................................... 4-14
Switch Combinations for A Triggering Checks ................................. 4-16
Adjustments Affected by Repairs ............................................ 5-2
Power Supply Limos ....................................................... 5-4
Deflection Accuracy Limits ................................................. 5-8
Store Deflection Accuracy ................................................. 5-10
Attenuator Compensation Adjustments ....................................... 5-11
Settings for Bandwidth Checks ............................................. 5-13
Settings for Timing Accuracy Checks ........................................ 5-18
Settings for Delay Time Differential Checks ................................... 5-19
Relative Susceptibility to Static-Discharge Damage ............................. 6-l
External Inspection Checklist ................................................ 6-2
Internal Inspection Checklist ................................................ 6-3
Timing Switch Interface Voltages. ............................................ 6-Q
Timing Switch Interface Voltages ............................................ 6-10
Vertical VOLTS/DlV Interface Voltages ........................................ 6-11
AC GND DC Switch Interface Voltages ....................................... 6-l 1
ProbeCoding ........................................................... 6-12
Power Supply Voltage and Ripple Limits ..................................... 6-l 3
DiagnosticTestsand Messages ............................................ 6-15
Error Codes for Pu Test ................................................... 6-17
Display Format for Front Panel IO Exerciser ................................... 6-18
OutputPortsExerclser .................................................... 6-19
Maintenance Aids ........................................................ 6-22
GPIB Status Brrffer Functions ................................................ 7-3
KS-232-C Status Buffer Functions ........................................... 7-4
Test Equipment Required ................................................... 7-5

2232 Setvlce
OPERATORS SAFETY SUMMARY
The safetv information in this summaw is for onerating personnel. Warnings and cautions will also be found throughout
the ma&al where they apply. . -.
Terms in This Manual Grounding the Product
CAUTION StStementS identify conditions Or practices
tnat could result In damage to the equipment or other
property.
WARNING statements identify conditions or practices
that could result in personal injuy or loss of life.
This product Is grounded through the grounding can-
ductor of the power cord. To avoid electrical shock, plu.
the power cord into a properly wired receptacle before
making any connections to the product input or output
terminals. A protoctlve ground connection, byway of the
grounding conductor in the power cord, Is essential for
safe operation.
Terms as Marked on Equipment
CAUTION indicates a personal injury hazard not immedi-
ately accessible as one reads the markings, or a hazard
to property, including the equipment itself.
DANGER lndlcates a personal injury hazard immediately
accessible as one reads the marking.
Symbols in This Manual
This symbol indicates where applicable
cautionary or other information is to
be found. FOrmaximum input voltage
see Table l-1,
Symbols as Marked on Equipment
DANGER-High voltage.
@ Protective ground (earth) terminal.
A ATTENTION-Refer to manual.
Power Source
Ttlis prOduct is Intended to operate from a power source
that does not apply more than 250 V rms between the
supply conductors or between either supply conductor
and ground. A protective ground connectlon, by way of
the grounding conductor in the power cord, is essential
for safe operation.
Danger Arising From LOSSof Ground
Upon loss of the protective-ground Connection, all
accessible conductive parts, including knobs and con-
trols that may appear to be insulating, can render an
electric shock.
Use the Proper Power Cord
Use only the power cord and COnnectOr specified for
your product.
Use only a power cord that Is In good condition. I
For detailed information on power COrdS and con-
nectors, see Figure 2-2. I
Use the Proper Fuse
To avoid fire hazard, use only a fuse of the correct type,
voltage rating and current rating as specified in the parts
list for your product.
Do Not Operate in an Explosive
Atmosphere
To avoid explosion, do not operate this instrument in an
explosive atmosphere.
Do Not Remove Covers or Panels
To avoid personal injury, do not remove the product
covers or panels. Do not operate the product without the
covers and panels properly installed. e
VI
I

FOR QUALIFIED SERVICE PERSONNEL ONLY
Refer also to the preceding Operators SafetySuiwmy
Do Not Service Alone
Do not perform internal service or adjustment of this
product unless another person capable of rendering first
aid and resuscitation Is present
Use Care When Servicing With Power On
Dangerous voltages exist at several points in this
product. To avold personal injury, do not touch exposed
connections or components while power is on.
Disconnect power before removing protective panels,
soldering. or replacing components.
Power Source
This product is intended to operate from a power source
that does not apply more than 250 volts rms between the
supply conductors or between either supply conductor
and ground. A protective ground connection by way of
the grounding connector In the power cord is essential
for safe operation.

2232 Servlce
The 2232 Dlgltal Storage Oscilloscope.
viii

Section 1-2232 Service
SPECIFICATION
INTRODUCTION
The TEKTRONIX 2232 is a combination nonstorage and
digital storage portable, dual-channel oscilloscopewith
100 MHz analog bandwidth and up to 100 MS/s digital
sampling rate. The vertical channels have calibrated
deflection factors from 2 mV to 5 V per division. The
Variable VOLTS/DIV gain control increases the deflec-
tion factor at least 2.5 to 1 on any VOLTS/DIV setting.
Vertical display modes are CH 1, CH 2, and BOTH, with a
choice in BOTH of ADD, ALT, or CHOP A BW LIMIT
feature limits the vertical amplifier system and the A
Trigger system to 20 MHz.
The horizontal deflection system calibrated A Sweep
speeds range from 0.5 s to 50 ns per division; calibrated
B Sweep speeds range from 50 ms to 50 ns per division.
AXl 0 MAG control decreases sweep time per division of
the A and B Sweeps byafactor of 10. Thefastest sweep-
speed time of 50 ns per division is extended to 5 ns per
division in X10 MAG. The Variable SEC/DIV control may
be used to increase the non-store sweep time per
division by a factor of up to four times from the calibrated
time per divlslon determined by the SEC/DIV switch set-
ting. In STORE Mode, rotating thevariable SEC/DIVcon-
trol out of the CAL detent position compresses a 4K sam-
ple acquisition rscord into a record of IK samples
(called 4K compress mode). Also in STORE Mode, the A
SEC/DIV X10 Multiplier adds calibrated storage time
bases of 1,2, and 5 s per division to the NON STORE A
Sweep Speed range for low-frequency signal
acquisltlons.
The digital storage and display portlon of the 2232 is
microprocessor controlled. Selecting the digital storage
featUreS is done with a combination of front-panel
controls and menu choices. Selected front-panel
controls are read by the microprocessor to determine
their settings. Those settings are reported to the user In a
crt readout display generated for the CH 1 and CH 2
VOLTS/DIV switch, the A and B SEC/DIV switch, tile
DELAY TIME Position control, the Voltage and Time
cursor differences (on STORE Mode displays only), the
position Of AC-GND-DC switches, and the A Trigger
LEVEL voltage level. All the parametric information for
the waveform display is therefore visible when a hard
copy is made to maintain a permanent record of the
misplay. wnen in STORE (digital) mode, additional
readout information is displayed showing storage
acquisition mode, SAVE REF memories, if diSplayad,
SAVE mode, and SWEEP LIMIT, if active.
Digital storage maxlmum sampling rate is 100
megasamples per second with a maximum stored
record length per waveform of either 4096 bytes (4K) for
single-channel acquisitions or 2048 bytes (2K) for dual-
channel acquisitions (ALT or CHOP). In CHOP mode,
both channels are sampled simultaneously. The digital
storage acquisition system has glitch-catching
capabilities for glitch widths as narrow as 10 ns.
Up to three waveform sets (CH I and/or CH 2) of IK
record length (512 data points each waveform for dual-
channel acquisitions) or one waveform set of 4K record
lengtn (2K when dual-channel) may be stored in the
SAVE REF memories. In either case, previous data is
over-written. A saved waveform may be recalled for
display and comparison with the current acquisition
waveform and any or all of the other saved waveforms.
The X10 MAG control is also functional for STORE
waveforms and provides for horizontal expansion of 10
times. The CURSOR Control may be used to reposition
the display window on X10 expanded STORE
waveforms to vlew the entire acquisition.
On stored waveforms (current acquisition and saved dis-
plays), voltage and time measurements may be made
using CURSORS. The cursors are positioned to the
waveform of interest and then to the points of interest in
the waveform. The AV and At crt readouts indicate the
voltage difference and timing difference between the
positions of the cursors on the waveform selected. Hori-
zontal positioning of the 1K display window within a 4K
acquisition record is also provided by the CURSOR
Posltloning control. In this manner, the entire 4K record
length may be scrolledthrough for display on the crt. The
displayed 1K window of a 4K record length acquisition
waveform is the data stored when using the SAVE REF
memory to savs 1K waveform data. A 4K record length
acquisition may also be compressed to a IK record
length by rotating the variable SEC/DIV control away
from the CAL detent position. The complete waveform is
then only one display window in length. A 4K compress
waveform may be saved in any of the three 1KSAVE REF
memories.
ACCURACY AND RESOLUTION
Finite resolution affects any measurement using discrete
numbers. All digital storage stores amplitude values as
discrete numbers and associates those amplitude
1-l