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 PERFOR ANY
SERVICING OTHER THAN THAT CONTAINED IN
OPERATING INSTRUCTIONS UNLESS YOU ARE
QUALIFIED TO DO SO. REFER TO OPERATORS
SAFETY SU ARY AND SERVICE SAFETY SU 
ARY PRIOR TO PERFOR ING ANY SERVICE.
Please Check for
CHANGE INFORMA TION
at the Rear of This Manual
First Printing JUL 1988
Revised JU 1989 Tfektronix
C O M M I T T E D TO E X C E L L E C E

Copyright © 1988 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.
TEKTRO IX, TEK, SCOPE-MOBILE, and are registered
trademarks of Tektronix, Inc.
Printed in U.S.A. Specification and price change privileges are
reserved.
Instrument Serial Numbers
Each instrument has a serial number on a panel 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, V, Heerenveen.The etherlands

TABLE OF CONTENTS
2440 Service
Page
LIST OF ILLUSTRATIONS ........................................ iii
LIST OF TABLES...................................................... v
OPERATORS SAFETY SU ARY . .......................... vi
SERVICING SAFETY SU ARY .............................. vii
Section 1 SPECIFICATIO
I TRODUCTIO ................................. 1-1
PERFORMA CE CO DITIO S ....... .. 1-4
Section 2 PREPARATIO FOR USE
SAFETY ............................................. 2-1
LI E VOLTAGE SELECTIO ............. 2-1
LI E FUSE ........................................ 2-1
POWER CORD................................... 2-3
I STRUME T COOLI G ................... 2-3
START-UP ..... ! ................................... 2-3
POWER-DOW .................................. 2-4
REPACKAGI G FOR SHIPME T ...... 2-4
Section 3 THEORY OF OPERATIO
SECTIO ORGA IZATIO ................ 3-1
I TEGRATED CIRCUIT
DESCRIPTIO S................................. 3-1
SIMPLIFIED BLOCK DIAGRAM
DESCRIPTIO ........................................ 3-2
DETAILED BLOCK DIAGRAM
DESCRIPTIO ....................................... 3-8
I TRODUCTIO ....... . ......................... 3-8
I PUT SIG AL CO DITIO I G
A D A ALOG SAMPLI G............ . 3-8
ACQUISITIO PROCESS
A D CO TROL.................................. 3-10
DATA CLOCKI G TO
ACQUISITIO MEMORY ................... 3-10
A ALOG DATA CO DITIO I G
A D A/D CO VERSIO .................... 3-11
ACQUISITIO PROCESSI G
A D DISPLAY.................................... 3-12
DETAILED CIRCUIT
DESCRIPTIO ....................................... 3-15
SYSTEM PROCESSOR ..................... 3-15
WAVEFORM PROCESSOR
SYSTEM ............................................ 3-22
Page
FRO T PA EL PROCESSOR ............ 3-28
FRO T PA EL CO TROLS ............... 3-30
SYSTEM DAC A D ACQUISITIO
CO TROL REGISTERS....................... 3-31
SYSTEM DAC (cont) A D
AUXILIARY FRO T PA EL................. 3-33
SYSTEM CLOCKS............................... 3-35
TIME BASE CO TROLLER
A D ACQUISITIO MEMORY ......... .. 3-39
ATTE UATORS A D
PREAMPLIFIERS................................. 3-43
PEAK DETECTORS A D
CCD/CLOCK DRIVERS ....................... 3-45
TRIGGERS A D PHASE CLOCKS .... 3-51
JITTER CORRECTIO RAMPS ......... 3-56
TRIGGER HOLDOFF, JITTER
COU TERS, A D CALIBRATOR ...... 3-58
CCD OUTPUT...................................... 3-61
A/D CO VERTER A D
ACQUISITIO LATCHES .............. , .... 3-62
DISPLAY A D ATTRIBUTES
MEMORY.............................................. 3-63
DISPLAY CO TROL ........................ 3-66
DISPLAY OUTPUT .............................. 3-73
HIGH VOLTAGE POWER
SUPPLY A D CRT ............................. 3-75
SYSTEM I/O.......................................... 3-80
VIDEO OPTIO .................................... 3-84
LOW VOLTAGE POWER SUPPLY .... 3-92
LOW VOLTAGE REGULATORS ........ 3-98
Section 4 PERFOR ANCE CHECK AND
FUNCTIONAL VERIFICATION
PROCEDURE
I TRODUCTIO ..................................... 4-1
PREPARATIO .................................. 4-1
I ITIAL SETUP..... .............................. 4-4
VERTICAL SYSTEM ................ 4-6
TRIGGERI G SYSTEMS ......................... 4-18
HORIZO TAL SYSTEM .......................... 4-26
ADDITIO AL VERIFICATIO S
A D CHECKS..................................... 4-29

2440 Service
TABLE OF CONTENTS (cont)
Page
Section 5 ADJUSTME T PROCEDURE
I TRODUCTIO . .......... 5-1
: CALIBRATIO SEQUE CE A D
PARTIAL PROCEDURES ................... 5-1
WARM-UP TIME REQUIREME T ..... 5-1
PRESERVATIO OF
I STRUM E T - *
CALIBRATIO ...... . .............................. 5-2
I TER AL ADJUSTME TS .... . ............... 5-3
SELF CALIBRATIO . ............................... 5-19
EXTER AL CALIBRATIO ..................... 5-20
Section 6 MAI TE A CE
I STRUME T CALIBRATIO ............ 6-1
ATIO AL BUREAU OF
STA DARDS TRACEABILITY .... . ...... 6-2
VOIDI G CALIBRATIO ..... . ............... 6-2
STATIC-SE SITIVE COMPO E TS ...... 6-3
PREVE TIVE MAI TE A CE ................ 6-4
I TRODUCTIO .................. . ................ 6-4
GE ERAL CARE..... ... .................... 6-4
I SPECTIO A D CLEA I G ........... 6-4
LUBRICATIO ...................................... 6-6
SEMICO DUCTOR CHECKS ............. 6-6
PERIODIC READJUSTME T ............. 6-6
TROUBLESHOOTI G ......... . ...... 6-7
I TRODUCTIO .............. 6-7
TROUBLESHOOTI G AIDS .......... . 6-7
TROUBLESHOOTI G
EQUIPME T......................................... 6-9
TROUBLESHOOTI G
TECH IQUES ......... ............................. 6-9
CORRECTIVE MAI TE A CE ............ . 6-11
I TRODUCTIO .... ................ : ............. 6-11
MAI TE A CE PRECAUTIO S ........ 6-11
OBTAI I G REPLACEME T
PARTS.. ........ . .................... 6-11
MAI TE A CE AIDS.... ..................... 6-12
. I TERCO ECTIO S ........................ 6-12
TRA SISTORS A D
I TEGRATED CIRCUITS .................... 6-12
SOLDERI G TECH IQUES ............... 6-14
REMOVAL A D REPLACEME T
PROCEDURE....................................... 6-15
Page
DIAG OSTICS A D
I TER AL CALIBRATIO
ROUTI ES . .......... 6-25
I TRODUCTIO ....... .... . ........ 6-25
OVERVIEW......................................... 6-25
CALIBRATIO ROUTI ES .............. 6-25
DIAG OSTIC ROUTI ES . ......... 6-27
DIAG OSTICS OPERATIO
VIA THE GP1B I TERFACE................ 6-34
DIAG OSTIC PROCEDURES.. .......... 6-35
Section 7 OPTIONS AND ACCESSORIES
OPTIO S DESCRIPTIO ................... 7-1
OPTIO S A1-A5:—I TER ATIO AL
POWER CORDS . .......... 7-1
OPTIO 1R—RACKMOU TED
2440 ....................................................... 7-1
OPTIO 03—WORD
RECOG IZER PROBE ....... . .............. 7-2
OPTIO 05—VIDEO OPTIO ............ 7-2
OPTIO 11 —PROBE POWER ........... 7-2
STA DARD ACCESSORIES.............. 7-2
RACKMOU TI G ACCESSORIES .... 7-2
OPTIO AL ACCESSORIES..... ........... 7-2
Section 8 REPLACEABLE ELECTRICAL PARTS
Section 9 DIAGRA S
Section 10 REPLACEABLE ECHANICAL PARTS
CHANGE INFOR ATION
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

2440 Service
LIST OF ILLUSTRATIONS
Figure Page
The 2440 Digital Oscilloscope................................................................................................. viii
1- 1 Dimensional drawing .............. ................................................................................................. 1-24
2- 1 LI E VOLTAGE SELECTOR, line fuse, and power cord receptacle...................: .................... 2-1
3- 1 2440 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 4 through 6 ........... 5-4
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 (S B010250 & Above) CH 1 and CH 2 CCD Clock Adjustments
(shown centered, as after doing part b).................................................................................. 5-7
5-4 (S B010249 & Below) CH 1 and CH 2 CCD 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 1 before L-clock adjustment................................................................. 5-12
5-7 Sides 1 and 3 before adjustment of LIS and after.................................................................. 5-13
5-8 CH 1 with L-clocks correctly adjusted, but with stray samples............................. 5-14
5-9 Display for adjusting CCD A and T clocks .................... 5-15
5-10 Typical CH 1 and CH 2 displays after clock adjustment......................................................... 5-16
5-11 Checking sample dispersion ........................................................... 5-17
5- 12 Input and output (after adjustment) waveforms ...................................................................... 5-20
6- 1 Multipin connector.................................................................................................................. 6-8
6-2 Circuit board Location............................................................................................................ 6-16
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
REV SEP 1988

2440 Service
LIST OF ILLUSTRATIONS (cont)
Page
6-8 Typical Register test waveforms................................. 6-55
6-9 Front Panel tiP diagnostics test................................................................................................ 6-79
6-10 System mP data bit D7 in the Bus Isolate mode .................................................... 6-102
9-1 Color codes for resistors and- capacitors. - ------- - ‘“ "" . ..........
9-2 Semiconductor lead configurations.
9-3 Locating components on schematic diagrams and circuit board illustrations.
9-4a Detailed 2440 Block Diagram.
9-4b Detailed 2440 Block Diagram (cont).
9-5 A12—Processor Board.
9-6 A13—Side Board.
9-7 A14—Front Panel Board.
9^8 A10—Main Board.
9-9 A30, A31, A32 and A33—Gain Cell Boards.
9-10 A ll—Timebase/Display Board.
9-11 A17—High Voltage Board.
9-12 A16—Low Voltage Power Supply Board.
r
IV

2440 Service
Table
1-1
1-2
1-3
1- 4
2- 1
3-1
3-2
3-3
3-4
3-5
3-6
3-7
3- 8
4- 1
4-2
4-3
4-4
6-1
6-2
6-3
6-4.
6-5
6-6
6-7
6-B
LIST OF TABLES
Page
Electrical Characteristics............................................................................... * ..................... 1-5
Environmental Characteristics .......... . ................................................................................... 1-19
Mechanical Characteristics................................................................................................... 1-21
Option 05 (TV Trigger) Electrical Characteristics.................................................................. 1-22
Voltage, Fuse, and Power-Cord Data........................... 2-2
Host Memory-Mapped I/O................................................................................................ 3-20
Processor Control Register Functions ................................................................................. 3-21
Processor Miscellaneous Register (PMREG) Output Functions............................................ 3-22
Waveform fiP Address Decoding.......................................................................................... 3-27
Trigger Logic Array Addresses (6080h-6087h)..................................................................... 3-52
Phase Clock Array Control Lines (CC3 through CCO) .......................................................... 3-55
Holdoff Delay Range for Current Source vs Charging Capacitor
Combinations....................................................................................................................... 3-59
Side Board Address Decoding............................................................................................. 3-60
Test Equipment Required.................................................................................................... 4-2
Accuracy Limits CH 1 and CH 2 CURSOR VOLTS Readout and A and
B TRIGGER LEVEL Readouts ...... . ...................................................................................... 4-10
Minimum Display Level for CH 1 or CH 2 Triggering ..................... 4-19
Minimum Signal Level for EXT1 or EXT2 Triggering............................................................ 4-21
Relative Susceptibility to Static-Discharge Damage............................................................. 6-3
External inspection Check List............................................................................................. 6-5
Internal Inspection Check List................................................................................................. 6-6
Power Supply Voltage and Ripple Limits .................................................. . ......................... 6-10
Maintenance Aids................................................................................................................ 6-13
2440 Troubleshooting Procedures........................................................................................ 6-37
Video Option Troubleshooting.................................................................. 6-104
I IT PA EL States.............................................................................................................. 6-108
V

2440 Service
OPERATORS SAFETY SU ARY
The eneral safety information in this part of the summary is for both operatin and servicin personnel.
Specific warnin s and cautions will be found throu hout the manual where they apply and do not appear in this
summary.
Terms in This anual Grounding the Product
CAUTIO statements identify conditions or practices that
could result in damage to the equipment or other property. This product is grounded through the grounding conductor
of the power cord. To avoid electrical shock, plug the
power cord into a properly wired receptacle before making
WAR I G statements identify conditions or practices that
could result in personal injury or loss of life. any connections to the product input or output terminals.
A protective ground connection by way of the grounding
conductor in the power cord is essential for safe operation.
Terms as arked on Equipment
CAUTIO indicates a personal injury hazard not immedi
ately accessible as one reads the markings, or a hazard to
property, including the equipment itself.
Danger Arising from Loss of Ground
Upon loss of the protective-ground connection, all accessi
ble conductive parts (including knobs and controls that
DA GER indicates a personal injury hazard immediately
accessible as one reads the marking. may appear to be insulated) can render an electric shock.
Symbols in This anual
This symbol indicates where applicable cau-
a 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 arked on Equipment Use the Proper Fuse
DA GER — High voltage. To avoid fire hazard, use only the fuse specified in the
instrument parts list. A replacement fuse must meet the
type, voltage rating, and current rating specifications for
the fuse that it replaces.
Protective gound (earth) terminal.
/ j \ ATTE TIO — Refer to manual. Do Not Operate in Explosive Atmospheres
To avoid explosion, do not Operate this instrument in an
atmosphere of explosive gasses.
Power Source
This product is intended to operate from a power source
that will 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 conductor in the power cord is essential for safe
operation.
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.

2440 Service
SERVICING SAFETY SU ARY
FOR QUALIFIED SERVICE PERSONNEL ONLY
Refer also to the precedin 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 a power source
that does not apply more than 250 volts rms bwetween
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.

■)
( )

Section 1—2440 Service
SPECIFICATION
INTRODUCTION
The TEKTRO IX 2440 Digital Oscilloscope is a
portable, dual-channel instrument with a maximum digitiz-
ing rate of 500 Megasamples per second. The scope is
capable of simultaneous acquisition of Channel 1 and
Channel 2 input signals. It has a real-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 a Word 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.
A user 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 1 of that manual fami
liarizes the user with menu operation.
VERTICAL SYSTE
The two vertical channels have calibrated deflection
factors from 2 mV to 5 V per division in a 1-2-5 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 V per division (with the 1000X probe)
and the maximum sensitivity to 200 /zV per division (using
a IX probe in SAVE or AVERAGE expanded mode).
VOLTS/DIV readouts are automatically switched to
display a correct 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 SYSTE
Horizontal display modes of A, A I TE , and B
Delayed are available. The time base has 29 calibrated
SEC/DIV settings in a 1-2-5 sequence from 2 ns per divi
sion to 5 s per division. An External Clock mode is
provided that accepts clocking signals from 1 MHz to
100 MHz.
The B Trace and the intensified zone on the A I TE
Trace may be delayed by time with respect to the A
trigger, and a DELAY by EVE TS function permits the A
display to be delayed by a selected number of B Trigger
events. In the case of DELAY by EVE TS, the B Trigger
SOURCE, COUPLI G, 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 1 to 65,536, with a resolution of
one event. The DELTA DELAY feature produces two
independently settable delayed B Traces in DELAY
by TIME.
TRIGGER SYSTE
The trigger system of the scope provides many features
for selecting and processing a signal 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 a conventional oscilloscope.
The choiees-of- VERT, CHI or CH2, EXTT or EXT2,
LI E, and A*B or WORD (16-bit data word recognition) are
available as SOURCE selections for triggering A Horizontal
Mode acquisitions. These sources for trigger signals
provide a wide range of applications involving specialized
triggering requirements. Except for A*B (A A D B) and
LI E (power-source frequency), the same Trigger
SOURCE selections are available for triggering B acquisi
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 OISE REJ. LEVEL
control provides a settable 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,
ORM, and SI GLE SEQ (single sequence), for the A and
A I TE SIFIED Modes, and Triggerabie After Delay and
Runs After Delay, for the B Mode. AUTO LEVEL provides
for automatic leveling on the applied trigger signal. AUTO
MODE produces an auto trigger in the event a trigger
signal is either not received or not within the limits needed
to produce a triggering event. When triggering conditions
are met, a normal 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.
ORM (normal) trigger MODE requires that all
triggering requirements are met before an acquisition will
take place. SI GLE SEQ (single sequence) MODE is a
variation of the conventional single-shot displays found on
many previous oscilloscopes, in SI GLE SEQ, a single
complete acquisition is done on all called-up VERTICAL
MODES. Since an acquisition depends oh the acquisition
mode in effect, many of the scope operating features are
altered in SI GLE SEQ. A complete1 description of this
mode is discussed in “Controls, Connectors, and
Indicators" in Section 5 of the Operators manual.
The user has a choice 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 a choice of five pretrigger lengths
beginning at one-eighth of the record length and increasing
to seven-eighths of the record length. A record trigger
position is independently selectable for both A and B
acquisitions. Additional trigger positions in the record are
selectable via the GPIB interface commands.
CURSOR EASURE ENTS
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 a selected 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 a waveform display
can be selected to read either the voltage difference
between the cursor positions or the absolute voltage posi
tion of a selected 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 a particular 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.
WAVEFOR ACQUISITION
Waveforms may be acquired in ORMAL, E VELOPE,
or AVG (Average) acquisition modes; the mode chosen
depends on the measurement requirements. ORMAL
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 a waveform
resulting in an improved signal-to-noise ratio of the
displayed waveform. Low-amplitude signals masked by
noise become easily visible for making measurements and
analysis by averaging from 2 to 256 acquisitions for
removing uncorrelated noise. E VELOPE mode saves the
1-2

Specification—2440 Service
maximum and minimum data-point values over a selected
number of acquisitions from 1 to 256 plus CO T (continu
ous). The display presents a visual image of the amount of
change (envelope) that occurs to a waveshape during the
accumulated acquisitions. Frequency, phase, amplitude,
and position changes are easily identified when acquiring
in E VELOPE mode. The glitch-catching capability of
E VELOPE mode can capture single-event pulses as nar
row as 2 ns at the slowest SEC/DIV setting of 5 seconds
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 a periodic
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 2 ns/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 a predetermined
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 E VELOPE mode),
of which 500 make up a one-screen display (50 data
points per division for 10 divisions). The entire record may
be viewed by using the Horizontal POSITIO 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 1 or channel 2 (or the results of an addition or multipli
cation of the two channels) to any REF memory or to
move a stored 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 a production 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
a system 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 a viewable display based
on the input signal. The user can specify the waveform
characteristic the display is optimized for (front-edge,
period, etc.) from a menu displayed upon executing Auto
Setup.
MEASURE: MEASURE automatically extracts
parameters from signal input to the scope. In the
"S APSHOT” mode, 20 different waveform parameters
are extracted and displayed for a single 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 period of at least 20 minutes and is operating at an
can save single front-panel setups or sequences of setups ambient temperature between — 1B°C and +55° 6 (unless
and associated flow control and Input/Output actions fdr otherwise noted),
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- Items listed in the “Performance Requirements" column
panel setups (depending on complexity) can be stored in are verifiable qualitative or quantitative limits that define
one or more sequences. the measurement capabilities of the instrument.
The complete descriptions of these four features are
found in Section 5 of the Operators manual included with
this instrument.
The following items are standard accessories shipped
with the scope Instrument:
2 Probe packages
“Snap=loclca " ’ '' '
1 Zip-lock accessories pouch
1 Operators manual
1 Programmer's Reference Guide
2 Users Reference Guide
1 Fuse
1 Power cord (installed)
1 Blue plastic CRT filter (installed)
1 Clear plastic CRT filter
1 Front-panel cover
For part numbers and further information about
standard accessories and a list 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.
Environmental characteristics are given in Table 1-2.
The scope meets the environmental requirements of MIL
T-288000 for Type III, Class 3, Style D equipment, 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 vibratibn arid shock requirements of
MIL-T-28800C for Type III, Class 5, Style D equipment
when mounted using the rackmount rear-supportJdi j3,up-.
p li^l ’TFf'^Op-ton and the Rackmount
Conversion kit.
Mechanical characteristics of the scope are listed in
Table 1-3.
Video Option characteristics are .given in Table 1-4.
RECO ENDED ADJUST ENTS SCHEDULE
For optimum performance to specification, the internal
SELF CAL should be done:
PERFOR ANCE 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 a warmup
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 SYSTE —CHANNEL 1 AND CHANNEL 2
Resolution 8 bits.8
Displayed vertically with 25 digitization levels (DL)b per 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 2 ns
Repet OFF -113 to +112 DL’S.
Repet O 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 s per
division to 100 ns per division).
Sensitivity
Range 80 fiV per DL to 0.2 V per DL in a 1-2-5 sequence of 11 steps
(2 mV per division to 5 V per division).
Accuracy
ormal and Average Modes Within ± (2% + 1 DL) at any VOLTS/DIV setting for a signal
1 kHz or less contained within ±75 DL (±3 divisions) of center
when a SELF CAL has been performed within ± 15°C of the
operating temperature. Measured on a four- or five-division signal
with VOLTS or V@T cursors; U ITS set to delta volts.
Envelope Mode Add 1% to ormal Mode specifications.
Variable Range Continuously variable between VOLTS/DIV settings. Extends
sensitivity to 0.5 V per DL or greater, 12.5 V per division or
greater.
aPerformance Requirement not checked in the manual.
b"DL” is the abbreviation for “digitization level.” A DL 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/D1V setting of the channel used. Expressed as a voltage, a DL is equal to 1/25
of a division times the VOLTS/DIV setting.
REV OV 1988 1-5

Specification—2440 Service
Table 1-1 (cont)
Characteristics Performance Requirements
ACQUISITIO SYSTEM-—CHA EL , 1 A D CHA EL 2 (cont)
Bandwidth Bandwidth is measured with a leveled, low distortion, 50-Q source,
sine-Wave generator, terminated in 50 £2. The reference signal is
set to 6 divisions or to the maximum leveled amplitude obtainable
if the Volt/Div setting is too high to yield 6 div’s on screen.
Bandwidth with probe is checked using a probe-tip-to-GR
termination adaptor (017-0520-00).
Bandwidth with external termination is checked using a B C 50-Q
feed-through terminator (011-0049-01).
—3 dB Bandwidth
ormal or Average Modes. Envelope Mode
at SEC/DIV settings of 0.2 or faster. Using standard accessory probe or internal termination (not
checked with probe in manual).
—15°C to +30°C
+30°C to +55*C Dc to 300 MHz.
Upper Bandwidth Limit reduced by 2.5 MHz for each °C above
30° C.®
Envelope Mode at SEC/DIV settings of
0.5 (is or slower. be to 150 MHz using standard accessory probe, internal 50-£2
termination, or external 50-£2 termination on 1-M£2 input.®
—4.7 dB Bandwidth
ormal or Average Mode. Envelope Mode at
SEC/DIV settings of 0.2 (is or faster. Using 50-fl external termination on 1-MO input.
+30°C to +55°C Upper Bandwidth Limit reduced by 2.5 MHz for each °C above
30°C,a
Single Event Useful Storage Bandwidth
ormal or Average Mode, SEC/DIV at
0.1 fis or Faster; Repet OFF DC to 200 MHz (calculated).
. , « „ f"(sample freq max)0
U b b — 2 .5
AC Coupled Lower —3 dB Point
IX Probe 10 Hz or less.®
10X Probe 1 Hz or less.®
Step Response, Repet and Average On;
Average Set to 16
Rise Time 1.17 ns or less (calculated).®
T, (in ns) = v rrr ‘
r v ; BW (in MHz)
Performance Requirement not checked in the manual.
cSample freq. max. is 500 Hz.
1-6

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

Specification— 2440 Service
Table 1-1 (cont)
Characteristics Performance Requirements
ACQUISITIO SYSTEM--CHA EL 1 A D CHA EL 2 (cont)
Maximum input Voltages y |\
Input Coupling Set to DC, AC, or G D 400 V (dc + peak ac); 800 V p-p ac at 10 kHz or less.8
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.
POSITIO
Range - - - - ----------- "• '*• ‘ 3: (9.3 to ’10.4) div., at 50 mV per division with I VERT off, when
Self Cal has been done within ±5°C of the operating
temperature.
Gain Match between ORMAL and SAVE ±3 DLs for positions within ±5 divisions from center.
Low-Frequency Linearity
ormal or Average Mode 3 DLs or less compression or expansion of a two-division,
center-screen signal when positioned anywhere within the
acquisition window.
20-MHz Bandwidth Limiter
—3 dB Bandwidth 13 MHz to 24 MHz.
100-MHz Bandwidth Limiter
—3 dB Bandwidth 80 MHz to 120 MHz.
Rise Time 2.9 ns to 4.4 ns.a
With a five-division, fast-rise step (rise time of 300 ps or less)
using 50-Q dc input coupling and VOLTS/DIV setting of-10 mV 8
Performance Requirement not checked in the manual.
1-8

Specification—2440 Service
Table 1-1 (cont)
Characteristics Performance Requirements
TRIGGERI G—A and B
Minimum P-P Signal Amplitude for Stable® Triggering
from Channel 1, Channel 2, or ADD Source
A Trigger
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.
OISE REJ Coupled 1.2 divisions or less from DC to 50 MHz; increasing to 3 divisions
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.
B Trigger Multiply all A Trigger specifications by two.
A.B Selected Multiply all A Trigger specifications by two.
Minimum P-P Signal Amplitude for Stable Triggering®
from EXT TRIG 1 or EXT TRIG 2 Source
A Trigger
EXT Gain = 1
DC Coupled 17.5 mV from DC to 50 MHz, increasing to 50 mV at 300 MHz.
OISE 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 = -h5Amplitudes are five times those specified for Ext Gain = 1.
B Trigger Multiply all A Trigger amplitude specifications by two.
A.B Selected Multiply all A Trigger amplitude specifications by two.
aA stable trigger is one that results in a uniform, regular display triggered on the selected slope (±). A stably-triggered display
should NOT have the trigger point switch between opposite slopes on the waveform, nor should it “roll” across the screen, as suc
cessive acquisitions occur. At T1 E/DIV settings of 2 ms/DIV and faster, the TRIG’D LED is constantly lit if the display is stably
triggered (the LED can flash for SEC/DIV settings of 10 ms/DIV and slower).
1-9

Specification—2440 Service
Table 1-1 (Cont)
Characteristics Performance Requirements
TRIGGERING—A and B (cont)
Maximum P-P Signal Rejected by OISE REJ
Coupling Signals within the Vertical Bandwidth
Channel 1 or Channel 2 Source 0,4 division or greater for VOLTS/DIV settings of 10 mV and
higher.
Maximum noise rejected is reduced at 2 mV per division and
5 mV per division.
EXT TRIG 1 or EXT TRIG 2 Source 20 mV or greater when Ext Trig Gain = 1.100 mV or greater
when Ext Trig Gain = -f5.
EXT TRIG 1 and EXT TRIG 2 Inputs
Resistance rMfl±1%A
Capacitance 15 pF ±3 pF.a
Maximum input Voltage 400 V (dc + peak ac); 800 V p-p ac at 10 kHz or less.®
LEVEL Control Range
Channel 1 or Channel 2 Source ±18 divisions x VOLTS/DIV setting®
EXT TRIG 1 or EXT TRIG 2 Source
EXT GAI = 1 ±0.9 volt.®
EXT GAI = -s-5 ±4.5 volts.®
LEVEL Readout Accuracy (for triggering signals with
transition times greater than 20 ns)
Channel 1 or Channel 2 Source
DC Coupled
+ 15°C to+35°C Within ± [3% of setting + 3% of p-p signal + (0.2 division x
VOLTS/DIV setting) + 0.5 mV + (0.5 mV x probe attenuation
factor)].
— 15°C to -t-55°C (excluding +15°C to
-r35°C) ' Add (1.5 mV x probe attenuation) to +15°C to -j-35°C
specification.®
OISE REJ Coupled Add ± (0.6 division x VOLTS/DIV setting) to DC Coupled
specifications.
Checked at 50 mV per division.
•“Performance Requirement not checked in the manual.
1-10