Tektronix 7A13 User manual

Tektronix, Inc .
P.O . Box500
Beaverton, Oregon
97077

Serial Number
070-1948-00

First Printing APR 1975
N MANUAL

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CHANGE INFORMATION
'7A13 (SN B200000-up)
SECTION 1 SPECIFICATION
Page
Introduction 1-1
Electrical Characteristics 1-1
System Characteristics 1-4
Environmental Characteristics
1-4
SECTION 2 OPERATING INSTRUCTIONS
Introduction
2-1
Front Panel Description 2-1
Test Setup Chart 2-2
Familiarization Procedure 2-2
General
Operating Information 2-5
SECTION 3 CIRCUIT DESCRIPTION
Introduction
3-1
Block Diagram Description
3-1
Detailed Circuit Description 3-3
SECTION 4 MAINTENANCE
Preventive Maintenance 4-1
Troubleshooting 4-2
Corrective Maintenance 4-8
SECTION 5 PERFORMANCE CHECK/CALIBRATION
Introduction 5-1
Test Equipment Required 5-1
Short-Form Performance Check/Calibration
Procedure and Index
5-5
Performance Check/Calibration Procedure 5-8
SECTION 6 ELECTRICAL PARTS LIST
Abbreviations and Symbols
Parts Ordering Information
SECTION 7 DIAGRAMS AND CIRCUIT BOARD ILLUSTRATIONS
Symbols and Reference Designators
Voltage and Waveform Conditions
SECTION 8 MECHANICAL PARTS LIST
Mechanical Parts List Information
Index of Mechanical Parts Illustrations
Mechanical
Parts List
Accessories

7A13 (SN B200000-up)
Fig . 1-1 . 7A13 Differential Comparator .

Introduction
The 7A13 Vertical Plug-In is a DC coupled differential
comparator with
excellent common-mode rejection and
medium gain characteristics for
medium level
applications
. The 7A13 is designed for use in Tektronix

Common Mode
7000
series oscilloscopes . It may be used as a differential

Signal Range
input preamplifier
or conventional preamplifier in addition

1 mV/Div to
to its use as a comparator .

50 mV/Div ;
In the differential input mode, the dynamic range allows
the application
of common-mode signals up to +-10 or
--10 volts to be applied
to
the
unit without attenuation .
Common-mode rejection ratio of at least
20,000 :1 at DC to
100 kHz permits measurements of differential signals
less
thanl mV in amplitude on10volt common-mode signals .
When used
as a differential comparator, the 7A13 has
an effective offset range of 10,000
divisions .
Electrical
Characteristics
The electrical
characteristics described in fable 1-1 are
valid over the stated environmental
range of instruments
calibrated at an ambient temperature
of +20°C to-+-30°C
and
after a 20-minute warmup period unless otherwise
noted .
TABLE
1-1 (cont)
yV` ~Characteristic

-

Performance Requirement
X10
Vc In
10 mV/Div
to
50 mV/Div ;
X10 VC Out
0 .1 V/Div to
0 .5 V/Div ;
X10V
c In
0 .1 V/Div to
0 .5 V/Div ;
X10V
c Out
1
V/Div to 5 V/Div
X10 V
c
In
Frequency Response
(8 Div Reference)
Section 1---7A13 (SN B200000-up)
At least +-10 V and -10 V
At least -+-100 V and ---100 V
At least
-i-500 V and ---500 V
At least +500 V and -500 V
ELECTRICAL
Characteristic
TABLE 1-1
CHARACTERISTICS
PerformanceRequirement
FULL Bandwidth
Upper Limit
AC
(Capacitive)
Coupled Input
See Table 1-4, System
Charac-
teristics
10 Hz or less
Lower
Bandwidth
Deflection Factor
Frequency
(VOLTS/DIV)
Calibrated Range 1 mV/Div to 5 V/Div,12 steps in a 1,
5 MHz Bandwidth DC to 5 MHz within 500 kHz
2,
5 sequence
Gain Ratio
Within 1 .5% of GAIN adjusted at 1
Accuracy mV/Div
Overdrive Recovery Recovers to within 2 mV
in 1 us
Uncalibrated
Continuously variable : extends (1X Attenuator
at (and 1 mV in 0 .1 ms) after a pulse
(Variable) deflection factor
to at least 1 mV/Div) of
-110V or
--10V, or
less,
12 .5 V/Div
regardless of pulse duration .

Specification---7A13 (SN B200000-up)
Common Mode
Rejection Ratio
1 mV/Div to
50 mV/Div
X10Vc In
DC to 100 kHz
Maximum Input
Voltage
DC
(Direct)
Coupled
DC t- Peak AC
1 mV/Div to
50 mV/Div
;
X10
Vc
In
10 mV/Div to
50 mV/Div ; X10
VC
Out ;
0 .1 V/Div to 5
V/Div ;
"TABLE 1-1 (cont)
At least 20,000 :1, 20 V P-P or less
test signal
At least
10,000
:1,
10
V P-P
or less
test signal
Decreases to 500 :1 at 10 MHz with
1 V P-P, then 200 :1 at 20 MHz
at 1 V P-P . See Fig . 1-2 .
At least 2,000 :1
At least 500 :1
400 VDC, 400 V Peak AC, 1
kHz
or
less
TABLE 1-1 (cont)
Characteristic

Performance Requirement
Input R and C
Resistance
Maximum Gate
Current
0°C to -1-35°C
Both Inputs
DC Drift
Drift With Time
(Ambient Temp-
erature and
Line
Voltage Con-
stant)
Short Term
Long Term
Drift With Ambient
Temperature
Line Voltage Con-
stant)
Displayed Noise
Tangentially Meas-
u red)
1 Mfg ±0 .15%
Approximately 20 .0 pF
Within + - 1% between all deflection
factors .
1 mV P-P
or
less or 0 .1 Div or less
(whichever is greater) any 1 minute
interval within 1 hour
after 20
minutes from turn-on .
1 mV P-P or less or 0 .1 Div
(whichever is greater) during
any
hour
after the first hour and 20
minutes from turn-on .
2 mV/10° C or less, 0 .2 Div/10° C
or
less (whichever is greater)
1 % or less shift within 20 ns of step
of fast rise squarewave
when
switching undriven
input from
GND to AC or DC
400 NV

or

less

at

1 mV/Div

in
Type 7700-Series
indicator os-
cilloscope
0Vto±10V
(0
.1%
of setting +3 mV)
0
.5
mV
or less

Specification-7A13 (SN B200000-up)
V
N
F
Jd
Oa
noMME
MISM
EMMI
WEEM
OEMIMM
ME
111NOW1110 so
" 0 6MI'll
ININMEMSE-11MM
n
nnuuW
n Ism
nmn
. . : . . .
.l
. . : __ .
Y
O
O
r
0
O
O
r
g
r
2
O
N
N
O
O
2
Y
O
Fig . 1-2 . Common mode rejection ratio
graph . It pertains to 1 mV/Div through
20 mV/Div deflection factors .

Specification--7A13 (SN B200000-up)
Storage
Weight
TABLE
1-2
7A13 tested alone (separate from
oscilloscope mainframe)
ENVIRONMENTAL CHARACTERISTICS
Characteristic
.M . .M
Performance
Requirements
a___ ._._ ._____ .___ . .~ .- .-~- .~- ._ .~ :-T
Temperature
Operating
System Characteristics
O' C to +50 0 C
-55° C to +75'C
15,000 feet
50,000 feet
Qualified
under National Safe
Transit Committee test procedure
TABLE 1-3
PHYSICAL CHARACTERISTICS
Size___
. . . _
il Fits all 7000-Series plug -in
com-
partments
.
3 .1 Pounds (1 .4 kilograms) .
The system characteristics listed in Table
1-4 specify
the performance
of the plug-in with various combinations
of
probesand in various indicator oscilloscopes .
~'EXT
CAL
1 .5
1 .5
TABLE 1-4
SYSTEM CHARACTERISTICS
(Indicator Oscilloscope : 7500-Series with P6053B
Probe .)
'Accuracy (%)
3 1 NT
ry CAL -
__
2 .5
__2
.5
._
4 1NT
CAL
3 .5
3 .5
100 I 3 .5 I 1 .5 I 2 .5 I 3 .5
(MHz) (ns)
55 6 .4
__ . . .55_ ._6
.4
(Indicator Oscilloscope : 7700-Series with P6053B Probe .)
__ i 00 __ . ._1_ 3 .5 __j___1, :5 _1__ .5___1 ._
3-555

L6
.4
'Accuracy percentages apply to
all deflection factors . Plug-in
GAIN must be set at the deflection factor designated at the
applicable position of the VOLTS/DIV switch . When a probe is
used, the GAIN mustbe set with the calibration signal
applied to
the probe tip .
2 EXTernal CALibrator, 0°C to - h-50°C : The plug-in GAIN is
set
(within 10°C of the
operating temperature) using an external
calibrator signal whose
accuracy is within 0 .25% .
3 INTernal CALibrator, -1-15°C to 1-35°C :
The plug-in GAIN is set
using the oscilloscope's
own calibrator and the instrument is
operating within the
+15o
C to -F 35 0 C range .
4 INTernal CALibrator, 0°C to -1-50°C : The plug-in
GAIN is set
(within 10 0 C of the operating
temperature) using the os-
cilloscope's own calibrator, and the instrument is
operating
within the 0° C to
-1_50°
C range .

R ;
n
~
~
00

Illuminates

when

switch

S10,
1-50 mV

located on left side
of
plug-in,
is
VAR IN ONLY

turned cw . This indicates a -!
Lamp

INPUT and -- INPUT impedanceof
approximately infinity whenever
the VOLTS/DIV switch
is
set
between 1 and 50 mV, VARIABLE
knob is pushed in and 1X probe is
used .
INTRODUCTION
This section opens with a brief functional description of
the front panel
controls and connectors (see Fig . 2-1) .
Following the
front-panel description is a familiarization
procedureand finally a general
discussion of
the opera-
tion of the 7A13 .
FRONT-PANEL DESCRIPTION
Fig . 2-1 . Front panel of 7A13 and location of R,, switch S10 .
Section 2----7A13
(SN
B200000-up)
NOTE
With
VOL
TS/DIV switch
set from .
1
V to 5 V, lamp
remains on but input impedance is -1 MQ and the
input attenuator is uncompensated .
COMPARISON
VOLTAGE
(VC)
-I- and --

Selects polarity of comparison vol-
Pushbuttons tage
.
VOLTS DISPLAY

Reads out the equivalent voltage
selected by the COMPARISON
VOLTAGE (Vc) COARSE, FINE,
VOLTS/DIV, and PULL VAR for
X10
Vc
controls .
COARSE Control

Varies the V
c
voltage from zero
to
ten volts .
2-'i

Operating Instructions-7A13 (SN B200000-up)
FINE Control

Provides more
precise control of
the V
c
voltage .
I- INPUT Connector Provides a means of connection
for signal measurement . It also
contains a third contact for probe
attenuation information . This
enables proper deflection factor
display on the CRT screen, and
proper volts display on 7A13 .
INPUT Mode

Selects AC,DC, GND or V c Mode
Switch

of coupling for the - INPUT
channel .
VOL"I`S/DIV Switch

Selects one of twelve volts per
division calibrated deflection fac-
tors .
VOLTS/DIV VARI-

Selects an uncalibrated deflection
ABLE CONTROL

factor somewhere between the
twelve settings . A minium of 2 .5
times the VOLTS/DIV switch set-
ting is provided . The UNCAL lamp
lights when the VARIABLE control
is
out
of
the
CAL detent
.
PULL VAR FOR X10

Extends the deflection factor of the
V
cSwitch

VOLTS/DIV Switch . This occurs
only for 10, 20, and 50 mV/DIV and
.1,
.2, and .5 V/DIV settings of the
VOLTS/DIV
switch .
--
INPUT Connector

Same as
for + INPUT connector .
INPUT Mode

Selects AC,DC, GND or
Vc
Mode
Switch

of coupling for the --- INPUT
channel .
STEP ATTEN BAL

Adjusts for no vertical trace move
Adjustment

ment as the
VOLTS/DIV switch
setting is varied
from
10 to
50 mV/DIV .
GAIN Adjustment

Adjusts the amplifier gain for dis-
play of four divisions upon receipt
of

a 4 mV signal when the
VOLTS/DIV switch is set to
1 mV
and the VARIABLE control is set to
CAL .
2-2
X10 BAL

Adjusts for no vertical trace move
Adjustment

ment as
VARIABLE (VOLTS/DIV)
knob is pulled out .
VAR BAL Control

Adjusts for no vertical trace move-
ment as VARIABLE (VOLTS/DIV)
knob is varied throughout its
range
.
Release Latch

Pull to withdraw plug-in from in-
dicator oscilloscope .
BW Switch

Selects either the FULL bandwidth
or 5 MHz .
V c OUT 0-10 V Jack

Provides
a
convenience outlet for
the comparison voltage .
POSITION Control

Positions display
vertically
on
the
CRT face .
V c REF-I DENT

Internally disconnects both
sig
Pushbutton

nals and applies V
c
to both inputs .
Readout display is replaced by the
word "IDENTIFY" .
TEST SETUP CHART
Fig . 2-2 shows a drawing of the front panel controls and
connectors . This chart can be reproduced and used as a
test setup record
for
special
measurements and
applications, or it may be used as a training aid for
operation of the 7A13 .
FAMILIARIZATION PROCEDURE
First-Time Operation
The following steps are
intended to help get the trace
on the CRT screen quickly and to prepare the unit for
immediateuse . These steps are intended to acquaint you
with some of the basic functions
of
the 7A13 .
1 .
Insert the unit into the oscilloscope vertical plug-in
compartment .