Tektronix 2440 User manual

TEK 070-6603-00
Product Group 37
2440
OSCILLOSCOPE
SERVICE
WARNING I
/the following servicing instructions are
*'for use by qualified personnel ONLY.- to
AVOID PERSONAL INJURY, DO NOT PERFORM ANY
SERVICING OTHER THAN THAT CONTAINED IN
OPERATING INSTRUCTIONS UNLESS YOU ARE
QUALIFIED TO DO SO. REFER TO OPERATORS
SAFETY SUMMARY AND SERVICE SAFETY SUM-
MARY PRIOR TO PERFORMING ANY SERVICE.
Please Check for
CHANGE INFORMATION
at the Rear of This Manual
First Printing JUL 1988
Revised JUN 1989 Tfektronix
COMMITTED TO EXCELLENCE

Copyright ©1588 Tektronix, Inc. Ail rights reserved. Contents of this
publication may not be reproduced in any form without the written
permission of Tektronix, Inc.
Products of Tektronix, Inc. and its subsidiaries are covered by U.S.
and foreign patents and/or pending patents.
TEKTRONIX, TEK, SCOPE-MOBILE, and
trademarks of Tektronix, Inc.
are registered
Printed in U.S.A. Specification and price change privileges are
reserved.
Instrument Serial Numbers
Each instrument has aserial number on apanel insert, tag, or
stamped on the chassis. The first number or letter designates the
country of manufacture. The last five digits of the serial number are
assigned sequentially and are unique to each instrument. Those
manufactured in the United States have six unique digits. The country
of manufacture is identified as follows:
BOOOOOO Tektronix, Inc., Beaverton, Oregon, USA
100000 Tektronix Guernsey, Ltd., Channel Islands
200000 Tektronix United Kingdom, Ltd., London
300000 Sony/Tektronix, Japan
700000 Tektronix Holland, NV, Heerenveen.The Netherlands

2440 Service
TABLE OF CONTENTS
Page
LIST OF ILLUSTRATIONS iii
LIST OF TABLES v
OPERATORS SAFETY SUMMARY vi
SERVICING SAFETY SUMMARY vii
Section 1SPECIFICATION
INTRODUCTION 1-1
PERFORMANCE CONDITIONS .. 1-4
Section 2PREPARATION FOR USE
SAFETY 2-1
LINE VOLTAGE SELECTION 2-1
LINE FUSE 2-1
POWER CORD 2-3
INSTRUMENT COOLING 2-3
START-UP !2-3
POWER-DOWN 2-4
REPACKAGING FOR SHIPMENT 2-4
Section 3THEORY OF OPERATION
SECTION ORGANIZATION 3-1
INTEGRATED CIRCUIT
DESCRIPTIONS 3-1
SIMPLIFIED BLOCK DIAGRAM
DESCRIPTION 3-2
DETAILED BLOCK DIAGRAM
DESCRIPTION 3-8
INTRODUCTION 3-8
INPUT SIGNAL CONDITIONING
AND ANALOG SAMPLING 3-8
ACQUISITION PROCESS
AND CONTROL 3-10
DATA CLOCKING TO
ACQUISITION MEMORY 3-10
ANALOG DATA CONDITIONING
AND A/D CONVERSION 3-11
ACQUISITION PROCESSING
AND DISPLAY 3-12
DETAILED CIRCUIT
DESCRIPTION 3-15
SYSTEM PROCESSOR 3-15
WAVEFORM PROCESSOR
SYSTEM 3-22
Page
FRONT PANEL PROCESSOR 3-28
FRONT PANEL CONTROLS 3-30
SYSTEM DAC AND ACQUISITION
CONTROL REGISTERS 3-31
SYSTEM DAC (cont) AND
AUXILIARY FRONT PANEL 3-33
SYSTEM CLOCKS 3-35
TIME BASE CONTROLLER
AND ACQUISITION MEMORY 3-39
ATTENUATORS AND
PREAMPLIFIERS 3-43
PEAK DETECTORS AND
CCD/CLOCK DRIVERS 3-45
TRIGGERS AND PHASE CLOCKS 3-51
JITTER CORRECTION RAMPS 3-56
TRIGGER HOLDOFF, JITTER
COUNTERS, AND CALIBRATOR 3-58
CCD OUTPUT 3-61
A/D CONVERTER AND
ACQUISITION LATCHES ,3-62
DISPLAY AND ATTRIBUTES
MEMORY 3-63
DISPLAY CONTROL 3-66
DISPLAY OUTPUT 3-73
HIGH VOLTAGE POWER
SUPPLY AND CRT 3-75
SYSTEM I/O 3-80
VIDEO OPTION 3-84
LOW VOLTAGE POWER SUPPLY 3-92
LOW VOLTAGE REGULATORS 3-98
Section 4PERFORMANCE CHECK AND
FUNCTIONAL VERIFICATION
PROCEDURE
INTRODUCTION 4-1
PREPARATION 4-1
INITIAL SETUP.... 4-4
VERTICAL SYSTEM 4-6
TRIGGERING SYSTEMS..... 4-18
HORIZONTAL SYSTEM 4-26
ADDITIONAL VERIFICATIONS
AND CHECKS 4-29

2440 Service
TABLE OF CONTENTS (cont)
Section 5ADJUSTMENT PROCEDURE Page
DIAGNOSTICS AND
Page
INTRODUCTION ..U.
CALIBRATION SEQUENCE AND ... 5-1 INTERNAL CALIBRATION
ROUTINES. ROR
PARTIAL PROCEDURES
.
... 5-1 INTRODUCTION ft OC
WARM-UPTIME REQUIREMENT...,... 5-1 OVERVIEW R-2R
PRESERVATION OF CALIBRATION ROUTINES
DIAGNOSTIC ROUTINES 6-25
—INSTRUMENT™ •
6-27
CALIBRATION ... 5-2 DIAGNOSTICS OPERATION
INTERNAL ADJUSTMENTS ... 5-3 VIA THE GPIB INTERFACE. 6-34
SELF CALIBRATION.... ,. 5-19 DIAGNOSTIC PROCEDURES 6-35
EXTERNAL CALIBRATION .. 5-20
Section 6MAINTENANCE
INSTRUMENT CALIBRATION 6-1
NATIONAL BUREAU OF
STANDARDS TRACEABILITY 6-2
VOIDING CALIBRATION .6-2
STATIC-SENSITIVE COMPONENTS 6-3
PREVENTIVE MAINTENANCE 6-4
INTRODUCTION...... 6-4
GENERAL CARE..... 6.4
INSPECTION AND CLEANING 6-4
LUBRICATION....... 6-6
SEMICONDUCTOR CHECKS 6-6
PERIODIC READJUSTMENT 6-6
TROUBLESHOOTING 6-7
INTRODUCTION ’. 6-7
TROUBLESHOOTING AIDS 6-7
TROUBLESHOOTING
EQUIPMENT 6-9
TROUBLESHOOTING
TECHNIQUES 6-9
CORRECTIVE MAINTENANCE 6-11
INTRODUCTION.... 6-11
MAINTENANCE PRECAUTIONS 6-11
OBTAINING REPLACEMENT
PARTS. 6-11
MAINTENANCE AIDS.... 6-12
INTERCONNECTIONS 6-12
TRANSISTORS AND
INTEGRATED CIRCUITS 6-12
SOLDERING TECHNIQUES 6-14
REMOVAL AND REPLACEMENT
PROCEDURE 6-15
Section 7OPTIONS AND ACCESSORIES
OPTIONS DESCRIPTION...
OPTIONS A1-A5—INTERNATIONAL
POWER CORDS .
OPTION 1R—RACKMOUNTED
2440
.. 7-1
.. 7-1
7-1
OPTION 03—WORD
RECOGNIZER PROBE .7-2
OPTION 05—VIDEO OPTION .7-2
OPTION 11—PROBE POWER .7-2
STANDARD ACCESSORIES .7-2
RA'CKMOUNTING ACCESSORIES.....7-2
OPTIONAL ACCESSORIES.... .7-2
Section 8REPLACEABLE ELECTRICAL PARTS
Section 9DIAGRAMS
Section 10 REPLACEABLE MECHANICAL PARTS
CHANGE INFORMATION
Diagnostic and Troubleshooting information:
Diagnostics 6_25
Diagnostic Operation 6-30
Diagnostic Procedures........ 6-32
2440 Troubleshooting Procedures Table 6-35
Video Option Troubleshooting Table 6-99
Troubleshooting Charts Section 9
ii

2440 Service
LIST OF ILLUSTRATIONS
Figure Pa9®
The 2440 Digital Oscilloscope viii
1-
1Dimensional drawing 1-24
2-
1LINE VOLTAGE SELECTOR, line fuse, and power cord receptacle :2-1
3-
12440 simplified block diagram 3-3
3-2 Simplified Memory Map of the 2440 3-18
3-3 System Clock waveforms 3-37
3-4 Simplified Peak Detector block diagram --3-47
3-5 Simplified CCD architecture —3-49
3-6 Trigger Logic Array Control Data Byte 3-53
3-7 Jitter correction waveforms 3-57
3-8 Readout State Machine flow chart 3-71
3-9 Vertical Vector Generator 3-73
3-10 DC Restorer 3-78
3-11 GPIB data flow diagram 3-81
3-12 GPIB three-wire handshake state diagram 3-82
3-13 Video Option waveforms 3-87
3-14 Video Option field-sync identification 3-88
3-15 'PWM Regulator and Inverter 3-94
3-16 PWM switching waveforms •• 3-96
5-1 Adjustment locations for Displays 4through 65-4
5-2 Display 5—Vertical and Horizontal Gain, Offset, and Vector
Compensation adjustment pattern 5-5
5-3 Display 6—Integrator Time adjustment pattern 5-6
5-4 (SN B010250 &Above) CH 1and CH 2CCD Clock Adjustments
(shown centered, as after doing part b) 5-7
5-4 (SN B010249 &Below) CH 1and CH 2CCD Clock Adjustments
(shown centered, as after doing part b) 5-8
5-5 CCD counts display and CM adjustment menu 5-8
5-6 CCD sides 1-4 for CH 1before L-clock adjustment 5-12
5-7 Sides 1and 3 before adjustment of LIS and after 5-13
5-8 CH 1with L-clocks correctly adjusted, but with stray samples 5-14
5-9 Display for adjusting CCD Aand Tclocks •5-15
5-1 0Typical CH 1and CH 2displays after clock adjustment 5-1
6
5-11 Checking sample dispersion 5-17
5-
12 Input and output (after adjustment) waveforms 5-20
6-
1Multipin connector 6-8
6-2 Circuit board Location 6-1 6
6-3 Installation sequence for installing the crt frame screws 6-23
6-4 Trigger LED binary coding for diagnostic tests 6-29
6-5 Main EXT DIAG Menu 6-30
6-6 Initial troubleshooting chart *6-36
6-7 Mux Test waveforms 6-41

2440 Service
LIST OF ILLUSTRATIONS (cont)
Page
6-8
6-9
6-10
9-1
9-2
9-3
9-4a
9-4b
9-5
9-6
9-7
9-8
9-9
9-10
9-11
9-12
Typical Register test waveforms
Front Panel ftP diagnostics test..
System fiP data bit D7 in the Bus Isolate mode
Color codes for resistors and- capacitors. * - —~———-———-
Semiconductor lead configurations.
Locating components on schematic diagrams and circuit board illustrations.
Detailed 2440 Block Diagram.
Detailed 2440 Block Diagram (cont).
A12—Processor Board.
A13—Side Board. !
A14—Front Panel Board.
A10—Main Board.
A30, A31, A32 and A33— Gain Cell Boards.
A1 1—Timebase/Display Board.
A17—High Voltage Board.
A16—Low Voltage Power Supply Board.
(
IV

2440 Service
LIST OF TABLES
Table Page
1-1 Electrical Characteristics
1-2 Environmental Characteristics
1-3 Mechanical Characteristics
1-4 Option 05 (TV Trigger) Electrical Characteristics
2-1 Voltage, Fuse, and Power-Cord Data
3-1 Host Memory-Mapped I/O
3-2 Processor Control Register Functions
3-3 Processor Miscellaneous Register (PM REG) Output Functions...
3.4 Waveform pPAddress Decoding
3-5 Trigger Logic Array Addresses (6080h-6087h)
3-6 Phase Clock Array Control Lines (CC3 through CCO)
3-7 Holdoff Delay Range for Current Source vs Charging Capacitor
Combinations
3-8 Side Board Address Decoding
3-20
3-21
3-22
3-27
3-52
3-55
3-59
3-60
4-1 Test Equipment Required
4-2 Accuracy Limits CH 1and CH 2CURSOR VOLTS Readout and Aand
BTRIGGER LEVEL Readouts .
4-3 Minimum Display Level for CH 1or CH 2Triggering
4_4 Minimum Signal Level for EXT1 or EXT2 Triggering
6-1 Relative Susceptibility to Static-Discharge Damage
6-2 External Inspection Check List
6-3 Internal Inspection Check List
6-4 Power Supply Voltage and Ripple Limits
6-5 Maintenance Aids
6-6 2440 Troubleshooting Procedures
6-7 Video Option Troubleshooting
6-8 INIT PANEL States.....
6-3
6-5
6-6
6-10
6-13
6-37
6-104
6-108
V

2440 Service
OPERATORS SAFETY SUMMARY
Thegenera! safety information in this part of the summary is for both operating and
Specific warnings and cautions will be found throughout the manuai where they apply and
summary.
servicing personnel,
do not appear in this
Terms in This Manuai
CAUTION statements identify conditions or practices that
could result in damage to the equipment or other property.
WARNING statements identify conditions or practices that
could result in personal injury or loss of life.
Terms as Marked on Equipment
CAUTION indicates apersonal injury hazard not immedi-
ately accessible as one reads the markings, or ahazard to
property, including the equipment itself.
DANGER indicates apersonal injury hazard immediately
accessible as one reads the marking.
Grounding the Product
This product is grounded through the grounding conductor
of the power cord. To avoid electrical shock, plug the
power cord into aproperly wired receptacle before making
any connections to the product^ input or output terminals.
Aprotective ground connection by way of the grounding
conductor in the power cord is essential for safe operation.
Danger Arising from Loss of Ground
Upon loss of the protective-ground connection, all accessi-
ble conductive parts (including knobs and controls that
may appear to be insulated) can render an electric shock.
Symbols in This Manual
This symbol indicates where applicable cau-
tionary or other information is to be found. For
maximum input voltage see Table 1-1.
Use the Proper Power Cord
Use only the power cord and connector specified for the
instrument.
Symbols as Marked on Equipment
ff DANGER —High voltage.
Protective gound (earth) terminal.
Use the Proper Fuse .
To avoid fire hazard, use only the fuse specified in the
instrument parts list. Areplacement fuse must meet the
type, voltage rating, and current rating specifications for
the fuse that it replaces.
A\ ATTENTION —Refer to manual.
Power Source
This product is intended to operate from apower source
that will not apply more than 250 volts rms between the
supply conductors or between either supply conductor and
ground. Aprotective ground connection by way of the
grounding conductor in the power cord is essential for safe
operation.
Do Not Operate in Explosive Atmospheres
To avoid explosion, do not operate this instrument in an
atmosphere of explosive gasses.
Do Not Remove Covers or Panels
To avoid personal injury, the instrument covers or panels
should only be removed by qualified service personnel. Do
not operate the instrument without covers and panels
properly installed.
(I J
vi

2440 Service
SERVICING SAFETY SUMMARY
FOR QUALIFIED SERVICE PERSONNEL ONLY
Refer also to the preceding Operators Safety Summary.
Do Not Service Alone
Do not perform internal service or adjustment of this pro-
duct 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 avoid personal injury, do not touch exposed connec-
tions or components while power is on.
Disconnect power before removing protective panels, sol-
dering, or replacing components.
Power Source
This product is intended to operate from apower source
that does not apply more than 250 volts rms bwetween
the supply conductors or between either supply conductor
and ground. Aprotective ground connection by way of the
grounding connector in the power cord is essential for safe
operation.

<• )
()

Section 1—2440 Service
SPECIFICATION
INTRODUCTION
The TEKTRONIX 2440 Digital Oscilloscope is a
portable, dual-channel instrument with amaximum digitiz-
ing rate of 500 Megasamples per second. The scope is
capable of simultaneous acquisition of Channel 1and
Channel 2input signals. It has areal-time useful storage
bandwidth of 200 MHz for single-event acquisitions, with
an equivalent-time bandwidth of 300 MHz when repetitive
acquisitions are acquired. Since both channels are
acquired simultaneously, the XY display is available to full
bandwidth. Options include aWord Recognition Probe,
Video signal triggering, Probe Power, and Rackmounting.
The instrument is microprocessor controlled and menu
driven, displaying at the top of the screen alphanumeric
CRT readouts of the vertical and horizontal scale factors,
trigger levels, trigger source, and cursor measurements.
Menus, displayed at the bottom of the CRT display, are
used by the operator to select the operating mode.
Auser makes decisions as to what operation and mode
setup the instrument must have to make the measurement
wanted and then selects the proper functions using a
combination of front-panel buttons and the
displayed menu.
Five menu buttons mounted on the CRT bezel are used
to make selections from the entry choices displayed. The
top line of the menu display usually contains the menu
title, and the bottom line labels the buttons with the
control functions they select. The selection is made
(indicated by an underscoring of the menu label in the
display) when the bezel button below the selected function
is pressed. The menus, system operating modes, and
auxiliary functions are described in Section 5, “Controls,
Connectors, and Indicators" of the Operators manual
included with this instrument, and the “Getting
Acquainted" procedure in Section 1of that manual fami-
liarizes the user with menu operation.
VERTICAL SYSTEM
The two vertical channels have calibrated deflection
factors from 2mV to 5Vper division in a1-2-5 sequence
of 14 steps. Use of coded probes having attenuation fac-
tors of IX, 10X, 100X, and 1000X extends the minimum
sensitivity to 5,000 Vper division (with the 1000X probe)
and the maximum sensitivity to 200 /A/ per division (using
aIX probe in SAVE or AVERAGE expanded mode).
VOLTS/DIV readouts are automatically switched to
display acorrect scale factor when properly coded probes
are attached. Each channel can be separately inverted.
ADD and MULT are display functions provided by the pro-
cessor system.
In SAVE mode, the waveforms may be both horizon-
tally and vertically repositioned, expanded horizontally and
vertically, added to each other, or multiplied together for
either XY or YT displays.
HORIZONTAL SYSTEM
Horizontal display modes of A, AINTEN, and B
Delayed are available. The time base has 29 calibrated
SEC/DIVsettings in a1-2-5 sequence from 2ns per divi-
sion to 5sper division. An External Clock mode is
provided that accepts clocking signals from 1MHz to
100 MHz.
The BTrace and the intensified zone on the AINTEN
Trace may be delayed by time with respect to the A
trigger, and aDELAY by EVENTS function permits the A
display to be delayed by aselected number of BTrigger
events. In the case of DELAY by EVENTS, the BTrigger
SOURCE, COUPLING, SLOPE, and LEVEL controls define
the nature of the signal needed to produce events
triggering. The number of events required to satisfy the
1-1

Specification—2440 Service
delay may be set from 1to 65,536, with aresolution of
one event. The DELTA DELAY feature produces two
independently settabie delayed BTraces in DELAY
by TIME.
TRIGGER SYSTEM
The trigger system of the scope provides many features
for selecting and processing asignal used in triggering the
acquisition system. The conventional features of SOURCE
selection, Trigger LEVEL control, Trigger SLOPE, Trigger
MODE, and CPLG (coupling) include enhancements not
normally found in aconventional oscilloscope.
-The choices of VERT, CHI or CH2, EXT1 or EXT2,
LINE, and A*B or WORD (16-bit data word recognition) are
available as SOURCE selections for triggering AHorizontal
Mode acquisitions. These sources for trigger signals
provide awide range of applications involving specialized
triggering requirements. Except for A*B (A AND B) and
LINE (power-source frequency), the same Trigger
SOURCE selections are available for triggering Bacquisi-
tions. The selected trigger signal is conditioned by the
choice of input CPLG (coupling). These coupling selections
are AC, DC, HF REF, LF REJ, and NOISE REJ. LEVEL
control provides asettable amplitude (with CRT readout)
at which triggering will occur, and SLOPE control deter-
mines on which slope of the triggering signal (plus or
minus) the acquisition is triggered.
Trigger MODE choices are AUTO LEVEL, AUTO,
NORM, and SINGLE SEQ (single sequence), for the Aand
AINTENSIFIED Modes, and Triggerable After Delay and
Runs After Delay, for the BMode. AUTO LEVEL provides
for automatic leveling on the applied trigger signal. AUTO
MODE produces an auto trigger in the event atrigger
signal is either not received or not within the limits needed
to produce atriggering event. When triggering conditions
are met, anormal triggered display results. At SEC/DIV
settings of 100 ms per division and longer, the AUTO
MODE switches to ROLL In ROLL MODE, the display is
continually updated and trigger signals are disregarded.
NORM (normal) trigger MODE requires that all
triggering requirements are met before an acquisition will
take place. SINGLE SEQ (single sequence) MODE is a
variation of the conventional single-shot displays found on
many previous oscilloscopes. In SINGLE SEQ, asingle
complete acquisition is done on all called-up VERTICAL
MODES. Since an acquisition depends on the acquisition
mode in' effect, many of the scope operating features are
altered in SINGLE SEQ. Acomplete description of this
mode is discussed in “Controls, Connectors, and
Indicators" in Section 5of the Operators manual.
The user has achoice of trigger points within the
acquired waveform record by selecting the amount of pre-
trigger data displayed. The trigger location in the record is
selectable from achoice of five pretrigger lengths
beginning at one-eighth of the record length and increasing
to seven-eighths of the record length. Arecord trigger
position is independently selectable for both Aand B
acquisitions. Additional trigger positions in the record are
selectable via the GPIB interface commands.
CURSOR MEASUREMENTS
Time and Voltage cursors are provided for making
parametric measurements on the displayed waveforms.
Time may be measured either between the cursor
positions (DELTA TIME) or between aselected cursor and
the trigger point of an acquired waveform (ABSOLUTE).
Time cursor readouts are scaled in seconds, degrees, or
percentage values. The 1/TIME cursors may be scaled in
hertz (Hz), degrees, or percentage.
Voltage cursor measurements on awaveform display
can be selected to read either the voltage difference
between the cursor positions or the absolute voltage posi-
tion of aselected cursor with respect to ground. The volts
measurement readouts may be scaled in units of volts,
decibels (dB), or percent. The Voltage cursors and Time
cursors may also be coupled to track together (V@T and
SLOPE) and assigned to aparticular waveform for ease in
making peak-to-peak and slope waveform measurements.
The units for V@T may be volts, percent, or dB; SLOPE
may have units of slope (VOLTS/SEC), percent
(VOLTS/VOLT), or dB.
WAVEFORM ACQUISITION
Waveforms may be acquired in NORMAL, ENVELOPE,
or AVG (Average) acquisition modes; the mode chosen
depends on the measurement requirements. NORMAL
mode Continuously acquires and displays successive
acquisitions producing a“live” waveform display similar to
that seen with an analog oscilloscope. AVG (averaging)
mode averages successive acquisitions of awaveform
resulting in an improved signai-to-noise ratio of the
displayed waveform. Low-amplitude signals masked by
noise become easily visible for making measurements and
analysis by averaging from 2to 256 acquisitions for
removing uncorrelated noise. ENVELOPE mode saves the
1-2

Specification—2440 Service
maximum and minimum data-point values over a selected
number of acquisitions from 1to 256 plus CONT (continu-
ous). The display presents avisual image of the amount of
change (envelope) that occurs to awaveshape during the
accumulated acquisitions. Frequency, phase, amplitude,
and position changes are easily identified when acquiring
in ENVELOPE mode. The glitch-catching capability of
ENVELOPE mode can capture single-event pulses as nar-
row as 2ns at the slowest SEC/DIV setting of 5seconds
per division.
For all three acquisition modes, equivalent-time sam-
pling extends the Useful Storage Bandwidth to 300 MHz if
the signal is repetitive and REPET mode is turned on. At
50 ns/DIV and faster, randomly-acquired data points (or
samples) taken from successive acquisitions of aperiodic
signal are used to fill the complete record (1024 data
points) of the signal waveform display. Depending on the
SEC/DIV setting, as few as 10 data points (at 2ns/DIV) or
as many as 512 data points (at 50 ns/DIV) may be
obtained on each triggered acquisition. Sampling of suc-
cessive acquisitions continues until apredetermined
number of data points are acquired and any remaining
points in the record are determined by interpolating
between the acquired points. (The predetermined number
includes at least enough data point to meet the Useful
Storage Bandwidth of 300 MHz specified for REPET
mode.) These interpolated points are replaced by
randomly-acquired data points as they become available
from successive acquisitions.
Horizontally, the record length of acquired waveforms is
1024 data points (512 max/min pairs in ENVELOPE mode),
of which 500 make up aone-screen display (50 data
points per division for 10 divisions). The entire record may
be viewed by using the Horizontal POSITION control to
position any portion of the record within the viewing area.
STORAGE AND I/O
Acquired waveforms may be saved in any of four REF
waveform nonvolatile memories. Any or all of the saved
reference waveforms may be displayed for comparison
with the waveforms being currently acquired. The source
and destination of waveforms to be saved may be user
designated. Assignment can be made to save either chan-
nel 1or channel 2(or the results of an addition or multipli-
cation of the two channels) to any REF memory or to
move astored reference from one REF memory to
another. Reference waveforms may also be written into a
REF memory location via the GPIB interface.
The scope is fully controllable and capable of sending
and receiving waveforms via the standard equipped GPIB
interface. This feature makes the instrument ideal for
making automated measurements in aproduction or
research and development environment that calls for
repetitive data taking. Self- calibration and self-diagnostic
features built into the scope to aid in fault detection and
servicing are also accessible via commands sent from the
GPIB controller.
Another standard feature is the “DEVICES” setting for
GPIB Interface control. This feature allows the user to out-
put waveforms (and other on-screen information) from the
front panel to many printers and plotters that use HP®
Graphics Language. In this way, hard copies of acquired
waveforms can be obtained without putting the scope into
asystem controller environment
EXTENDED FEATURES
There are several other features incorporated into this
instrument designed to make it more usable, namely, the
HELP, Auto Setup, MEASURE, and AutoStep
Sequencer features.
HELP: The HELP function can be used to display
operational information about any front-panel control.
When HELP mode is in effect, manipulating almost any
front-panel control causes the scope to display information
about that control. When HELP is first invoked, an
introduction to HELP is displayed on screen.
Auto Setup: The Auto Setup function is used to
automatically setup the scope for aviewable display based
on the input signal. The user can specify the waveform
characteristic the display is optimized for (front-edge,
period, etc.) from amenu displayed upon executing Auto
Setup.
MEASURE: MEASURE automatically extracts
parameters from signal input to the scope. In the
"SNAPSHOT” mode, 20 different waveform parameters
are extracted and displayed for asingle acquisition. In the
continuous extraction mode, up to four parameters are
extracted continuously as the instrument continues
to acquire.
1-3

Specification-—2440 Service
AutoStep Sequencer (PRGM): With AutoStep, the user
can save single front-panel setups or sequences of setups
and associated flow control and Input/Output actions for
later recall. If MEASURE and/or OUTPUT are saved as
part of these setups they can be used for automatic
parameter extraction and data printout. 100 to 800 front-
panel setups (depending on complexity) can be stored in
one or more sequences.
The complete descriptions of these four features are
found in Section 5of the Operators manual included with
this instrument.
The following items are standard accessories shipped
with the scope instrument:
2Probe packages
'“I"" Snap-lock accessories pouch"” *
™
1Zip-lock accessories pouch
1Operators manual
1Programmer's Reference Guide
2Users Reference Guide
1Fuse
1Power cord (installed)
1Blue plastic CRT filter (installed)
1Clear plastic CRT filter
1Front-panel cover
For part numbers and further information about
standard accessories and alist of the optional acces-
sories, refer to “Options and Accessories" (Section 7) in
this manual. For additional information on accessories and
ordering assistance, contact your Tektronix representative
or local Tektronix Field Office.
period of at least 20 minutes and is operating at an
ambient temperature between -15°C and +55°C (unless
otherwise noted).
Items listed in the “Performance Requirements" column
are verifiable qualitative or quantitative limits that define
the measurement capabilities of the instrument.
Environmental characteristics are given in Table 1-2.
The scope meets the environmental requirements of MIL-
T-28800C for Type III, Class 3, Style Dequipment, with
the humidity and temperature requirements defined in
paragraphs 3.9.2.2, 3.9.2.3, and 3.9.2.4. The rackmounted
scope meets the vibration and shock requirements of
MIL-T-28800C for Type III, Class 5, Style 0equipment
when mounted using the rackmounT rear-support kit sup-
pliecf ~wfth both' the ‘IR Option ancTthe Rackmount
Conversion kit.
Mechanical characteristics of the scope are listed in
Table 1-3.
Video Option characteristics are .given in Table 1-4.
RECOMMENDED ADJUSTMENTS SCHEDULE
For optimum performance to specification, the internal
SELF CAL should be done:
PERFORMANCE CONDITIONS
The following electrical characteristics (Table 1-1) apply
when the scope has been calibrated at an ambient tem-
perature between +20°C and +30°C, has had awarmup
1.If the operating temperature is changed by more
that 5°C since the last SELF CAL
was performed.
2. Immediately before making measurements
requiring the highest degree of accuracy.
1-4

Specification—2440 Service
Table 1-1
Electrical Characteristics
Characteristics Performance Requirements
ACQUISITION SYSTEM—CHANNEL 1AND CHANNEL 2
Resolution 8bits.8
Displayed vertically with 25 digitization levels (DL)bper division.
Dynamic Range8
SEC/DIV
100 or slower -128 to +127 DL’s.
50 to 500 ns -124 to +123 DL's.
200 ns ^121 to +120 DL’S.
100 ns -113 to +112 DL’s.
50 ns to 2ns
Repet OFF -113 to +112 DL’s.
Repet ON 121 to 120 DL’s.
Record Length 1024 samples.8
Displayed horizontally with 50 samples per division, 20.48-division
trace length.8
Sample Rate 10 samples per second to 500 megasamples per second (5 sper
division to 100 ns per division).
Sensitivity
Range 80 /xV per DL to 0.2 Vper DL in a1-2-5 sequence of 11steps
(2 mV per division to 5Vper division).
Accuracy
Normal and Average Modes Within ±(2% +1DL) at any VOLTS/DIV setting for asignal
1kHz or less contained within ±75 DL (±3 divisions) of center
when aSELF CAL has been performed within ±15°C of the
operating temperature. Measured on afour- or five-division signal
with VOLTS or V@T cursors; UNITS set to delta volts.
Envelope Mode Add 1% to Normal Mode specifications.
Variable Range Continuously variable between VOLTS/DiV settings. Extends
sensitivity to 0.5 Vper DL or greater, 12.5 Vper division or
greater.
aPerformance Requirement not checked in the manual.
b«DL” is the abbreviation for “digitization level.” ADL is the smallest voltage level change that can be resolved by the internal 8-bit
A-D converter, with the input scaled to the VOLTS/DIV setting of the channel used. Expressed as avoltage, aDL is equal to 1/25
of adivision times the VOLTS/DIV setting.
REV NOV 1988 1-5

Specification-—2440 Service
Table 1-1 (cont)
Characteristics Performance Requirements
ACQUISITION SYSTEM—CHANNEL 1AND CHANNEL 2(cont)
Bandwidth Bandwidth is measured with aleveled, low distortion, 50-fl source
sine-wave generator, terminated in 50 Q. The reference signal is
t0 ®?,~sions or to the max,mum leveled amplitude obtainable
if the Volt/Div setting is too high to yield 6div’s on screen.
Bandwidth with probe is checked using aprobe-tip-to-GR
termination adaptor (017-0520-00).
Bandwidth with external termination is checked usinq aBNC 50-J2
feed-through terminator (011-0049-01).
—3 dB Bandwidth
Normal or Average Modes. Envelope Mode
at SEC/DIV settings of 0.2 ns or faster.
—15°C to +30°C
+30°C to +55°C
Using standard accessory probe or internal termination (not
checked with probe in manual).
Dc to 300 MHz.
Upper Bandwidth Limit reduced by 2.5 MHz for each °C above
30°G-.a
Envelope Mode at SEC/DIV settings of
0.5 fis or slower. Dc to 150 MHz using standard accessory probe, internal 50-ft
termination, or external 50-S2 termination on 1-Mfi input a
—4.7 dB Bandwidth
Normal or Average Mode. Envelope Mode at
SEC/DIV settings of 0.2 (is or faster.
+30°C to +55°C
Using 50-fl external termination on 1-MQ input.
UpperBancIwicItli Limit reduced by 2.5 MHz for each °C above
oO C,.a
Single Event Useful Storage Bandwidth
Normal or Average Mode, SEC/DIV at
0.1 (is or Faster; Repet OFF DC to 200 MHz (calculated).
(j l"(samDle frea max)c
2.5
AC Coupled Lower —3 dB Point
IX Probe 10 Hz or less.3
10X Probe 1Hz or less. 3
Step Response, Repet and Average On;
Average Set to 1
6
Rise Time 1.17 ns or less (calculated). 3
Tr(in ns) =350 ,
rBW (in MHz)
Performance Requirement not checked in the manual.
cSample freq. max. is 500 MHz.
1-6

Specification—2440 Service
Table 1-1 (cont)
Characteristics Performance Requirements
ACQUISITION SYSTEM--CHANNEL 1AND CHANNEL 2(cont)
Envelope Mode Pulse Response
Minimum Single Pulse Width for 50% or Greater
Amplitude Capture at 85% or Greater Confidence
2ns.a
Minimum Single Pulse Width for Guaranteed 50%
nr Greater Amplitude Capture
8ns.a
Channel Isolation Measured with a10-division, sine-wave input and equal VOLT/DIV
settings on both channels. 100:1 or greater at 100 MHz for
VOLT/DIV settings from 2mV/DIV and 500 mV/DIV; 50:1 or
greater at 300 MHz for VOLT/DIV settings from 20 mV/DIV to
500 mV/DIV. 25:1 or greater at 300 MHz for VOLT/DIV settings
of 5mV/DIV and 10 mV/DIV.
Acquired Channel 2Signal Delay with Respect to
Channel 1Signal at Full Bandwidth
±250 ps.a
Input Rand C(1 MO)
Resistance 1MO ±0.5%.a
In each attenuator, the input resistance of all VOLTS/DIV
positions is matched to within 0.5%.a
Capacitance 15 pF ±2 pF.a
In each attenuator, the input capacitance of all VOLTS/DIV
positions is matched to within 0.5 pF.a
Input R(50 Q)
Resistance 50 0 +1%.a
VSWR (DC to 300 MHz) 1.3:1 or better. 3
Maximum Input Voltage 5Vrms; 0.5 W-sec for any one-second interval for instantaneous
voltages from 5Vto 50 V.
8Performance Requirement not checked in the manual.
1-7

Specification—2440 Service
fable 1-1 (cont)
Characteristics Performance Requirements
ACQUISITION SYSTEM—CHANNEL 1AND CHANNEL 2(cont)
Maximum Input Voltages ^
Input Coupling Set to DC, AC, or GND 400 V(dc +peak ac); 800 Vp-p ac at 10 kHz dr less.3
Common-Mode Rejection Ratio (CMRR); ADD Mode
with Either Channel Inverted At least 10:1 at 50 MHz for common-mode signals of 10 divisions
or less with VARIABLE VOLTS/DIV adjusted for best CMRR at
•50 kHz.
POSITION
Range —"(9-3 to 10-4) div., at 50 mV per division with INVERT off when
Self Cal has been done within ±5°C of the operatina
temperature. a
Gain Match between NORMAL and SAVE ±3 DLs for positions within ±5 divisions from center
Low-Frequency Linearity
Normal or Average Mode 3DLs or less compression or expansion of atwo-division,
center-screen signal when positioned anywhere within the
acquisition window.
20-MHz Bandwidth Limiter
—3dB Bandwidth 13 MHz to 24 MHz.
100-MHz Bandwidth Limiter
—3dB Bandwidth 80 MHz to 120 MHz.
Rise Time 2.9 ns to 4.4 ns.a
With afive-division, fast-rise step (rise time of 300 ps or less)
using 50-Q dc input coupling and VOLTS/DIV settinq of 10 mV a
aPerformance Requirement not checked in the manual.
1-8

Specification—2440 Service
Table 1-1 (cont)
Characteristics Performance Requirements
TRIGGERING—Aand B
Minimum P-P Signal Amplitude for Stable3Triggering
from Channel 1,Channel 2, or ADD Source
ATrigger
DC Coupled 0.35 division from DC to 50 MHz, increasing to 1.0 division at
300 MHz; 1.5 divisions at 300 MHz in ADD mode.
NOISE REJ Coupled 1.2 divisions or less from DC to 50 MHz; increasing to 3divisions
at 300 MHz; 4.5 divisions at 300 MHz in ADD mode.
AC Coupled 0.35 division from 60 Hz to 50 MHz; increasing to 1.0 division at
300 MHz; 1.5 divisions at 300 MHz in ADD mode. Attenuates
signals below 60 Hz.
HF REJ Coupled 0.50 division from DC to 30 kHz. Attenuates signals above
30 kHz.
LF REJ Coupled 0.50 division from 80 kHz to 50 MHz; increasing to 1.0 division at
300 MHz; 1.5 divisions at 300 MHz in ADD mode. Attenuates
signal below 80 kHz.
BTrigger Multiply all ATrigger specifications by two.
A.BSelected Multiply all ATrigger specifications by two.
Minimum P-P Signal Amplitude for Stable Triggering3
from EXT TRIG 1or EXT TRIG 2Source
ATrigger
EXT Gain =1
DC Coupled 17.5 mV from DC to 50 MHz, increasing to 50 mV at 300 MHz.
NOISE REJ Coupled 60 mV or less from DC to 50 MHz; increasing to 150 mV at
300 MHz.
AC Coupled 17.5 mV from 60 Hz to 50 MHz; increasing to 50 mV at 300 MHz.
Attenuates signals below 60 Hz.
HF REJ Coupled 25 mV from DC to 30 kHz.
LF REJ Coupled 25 mV from 80 kHz to 50 MHz; increasing to 50 mV at 300 MHz.
EXT Gain =-=-5 Amplitudes are five times those specified for Ext Gain =1.
BTrigger Multiply all ATrigger amplitude specifications by two.
A.B Selected Multiply all ATrigger amplitude specifications by two.
aAstable trigger is one that results in a
should NOT have the trigger point switch
cessive acquisitions occur. At TIME/DIV
triggered (the LED can flash for SEC/DIV
uniform, regular display triggered on the selected slope (±). Astably-triggered display
between opposite slopes on the waveform, nor should it “roll” across the screen, as sue-
settings of 2ms/DIV and faster, the TRIG’D LED is constantly lit if the display is stably
settings of 10 ms/DIV and slower).

Specification—2440 Service
Table 1-1 (cont)
Characteristics •Performance Requirements
TRIGGERING—Aand B(cont)
Maximum P-P Signal Rejected by NOISE REJ
Coupling Signals within the Vertical Bandwidth
Channel 1or Channel 2Source 0.4 division or greater for VOLTS/DIV settings of 10 mV and
higher.
Maximum noise rejected is reduced at 2mV per division and
5mV per division.
EXT TRIG 1or EXT TRIG 2Source 20 mV or greater when Ext Trig Gain =1. 100 mV or areater
when Ext Trig Gain «. -s-5. y
EXT TRIG 1and EXT TRIG 2Inputs
Resistance 1MO ±1%.a
Capacitance 15 pF ±3 pF. a
Maximum input Voltage 400 V(dc +peak ac); 800 Vp-p ac at 10 kHz or less.®
LEVEL Control Range
Channel 1or Channel 2Source ±18divisions xVOLTS/DIV setting.®
EXT TRIG 1or EXT TRIG 2Source
EXT GAIN =1±0.9 volt.®
EXT GAIN «= -r-5 ±4.5 volts. 3
LEVEL Readout Accuracy (for triggering signals with
transition times greater than 20 ns)
Channel 1or Channel 2Source
DC Coupled
+15°C to +35°CWithin ±[3% of setting +3% of p-p signal +(0.2 division x
VOLTS/DIV setting) +0.5 mV +(0.5 mV xprobe attenuation
factor)].
-15°C to -f55°C (excluding -f-15°C to
+35°C) Add (1.5 mV xprobe attenuation) to -f15°C to -f-35°C
specification. 3
NOISE REJ Coupled Add ±(0.6 division xVOLTS/DIV setting) to DC Coupled
specifications.
Checked at 50 mV per division.
aPerformance Requirement not checked in the manual.
1-10