HP 8082a Service manual

CERTIFICATION
The Hewlett-Packard Company certifies that this instrument was thoroughly
tested and inspected and found to meet its published specifications when
shipped from the factory. The Hewlett-Packard Company further certifies
that its calibration measurements are traceable to the US National Bureau of
Standards to theextentallowed by the Bureau’scalibration facilities or to the
calibration facilities of other International Standards Organization Members.
WARRANTY AND ASSISTANCE
XII Hewlett-Packard products are warranted against defects in materials and
workmanship. This warranty applies for one year from the date of delivery,
or, in the case of certain major components listed in the operating manual,
for the specified period. We will repair or replace products which prove to be
defective during the warranty period. No other warranty is expressed or
implied. We are not liable for consequential damages.
For any assistance contact your nearest Hewlett-Packard Sales and Service
Office. Addresses are provided at the back of this manual.
PREFACE
Qne copy of this manual is supplied with each instrument. Additional copies
may be purchased from the locai Hewlett-Packard Sales and Service Office.
Specify the instrument model number and serial number. A microfiche
version of this manual is availabie under part number 08082-90502
Reference should be made to the manual change sheeis supplied with the
manual for errata and technical changes, and Po Section 7 (Backdating/
Updating) ~
Technica! changes are indicated by the prefix (the first five characters) of the
serial number which appears on the rear panel of the instrument; the serial
number prefix of the instrument to which this manual applies directly is:

COMTENTS
Section 1General information
l-1 introduction ................................................. l-l
f-7 EClOlitput .................................................
l-4
Section 2Installation
2-7
2-1
2-2
2-4
2-6
2-8
2-9
2-12
2-15
2-17
2-19
2-26
2-22
General ..................................................... 2-l
initial Inspection
......................................... 2-l
Accessories
........................................... 2-1
PowerCords ........................................... 2-l
installation
................................................... 2-l
PowerCord ........................................... 2-1
Power Source Requirements
................................. 2-2
Temperature Requirements
................................. 2-2
Rack Mounting
............................................... 2-2
Claims and Repackaging
......................................... 2-3
Claims for Damage
....................................... 2-3
Repackaging for Shipment and Storage ......................... 2-3
Section 3Operating Instructions
3-1 General ..................................................... 3-l
3-4 Externat input Characteristics
..................................... 3-l
3-8
Square Wave Operation.
.......................................... 3-2
3-10 Output Amplitude Controls
....................................... 3-2
3-15 incompatible Control Settings
..................................... 3-2
3-17
NormOperatingMode
........................................... 3-2
3-20
EXTwidthOperatingMode
....................................... 3-3
3-22 Gate Operating Mode
........................................... 3-4
3-24 EXT Trig. Operating Mode
....................................... 3-4
3-26 Apptications Notes
............................................. 3-5
Section 4 Theory of Operation
4-l
4-8
4-21
4-28
4-36
4-38
4-44
44%
4-4%
4-50
introduction
................................................. 4-l
Repetition Rate Generator
.......................................
4-1
Delay and width Generators
....................................... 4-3
Slope Generator
............................................... 4-5
Buffer Amplifier
...............................................
4-6
Output Amplifier and Vernier Attenuators
.............................
4-6
DC offset for Positive Pulse Outputs
................................. 4-7
Step Attenuator
............................................... 4-7
~xter~a]DC~f~~
............................................. 4-7
Power Supplies
...............................................
4-7

List of Contents
CXXUTEMTS
Section 5Maintenance
5-l
5-4
5-4
5-7
5-9
5-12
5-15
5-21
5-24
5-28
5-32
5-39
5-41
5-45
5-46
5-46
General .............................. .5-l
Removal of Covers ...........................
5--f
Removal of Assemblies ..........................
5-l
General
..........................
.5-l
Power Supply Board - Assembly 2 ................
.5--l
Repetition Rate Generator Board - Assembly 3 ............
5-l
Output Amplifier Board - Assembly 4 ...............
5-l
Buffer Amplifier Board - Assembly 8 ..............
.5- 1
Output Ampiifier Board (A41 - Hybrid Circuit Renewal ........ 5-l
OffsetBoard-Assembly5 ................... .5-2
Mother Board - Assembly 1
....................5-2
Performance Checks ......................... .5-2
Internal Checks and Adjustments ............................ 5-17
Troubleshooting using the 15265 A Test Box
..................... 5-17
Safety Check
......................................
5-17
Tmubleshootiq Tips .................................. 6-l
7
Section 6Diagrams and Replaceable Parts
6-1
6-3
6-4
h?troduction
............................
.6-l
Ordering information ........................
.6--l
General
..........................
.6-d
Sction 7
7-l
7-3
7-5
7-7
Backdating
Serial Numbers 1419G96145 And Below
.......................... 7-l
Serial Numbers 14fOG99270 And Below ..........................
7-l
9erial Numbers t419G66271 to 1410669390 ......................
7-1
Serial Numbers 1416G66391 And Above ..........................
7-1
Page

Figure
2-a
2-2
2-3
2-4
2-5
3-1
3-2
3-3
3-5
3-6
3-7
3-8
3-9
3-10
3-11
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
5-l
5-2
6-l
Service Sheets
1
Repetition Rate Generator - Board A3 ............................... 6-17
2a
Delay and Width Generators - Part of Board A4 ......................... 6-21
Zb Slopa Generator
- Part of Board A4 and Buffer Amplifier - Soard A8 ......... 6-23
2c Output Amplifier
-Partof Board A4. ................................ 625
3a Slope Generator Current and Voltage Source
- Part of Board A5
............... 6-27
3b DC Offset and Amplitude Vernier
- Part of Board A5 ................... 6-29
4Step Attenuator
- Board A9 .....................................
6-31
5
Power Supplies - Board A2 ....................................... 6-33
Title
~.
8[182A and Supplied Accessories
................................... 2-9
Available Accessories
........................................... 2-6
Power Cords ................................................. 2-2
Switch Settings for the Various Nominal Powerline Voltages
................. 2-2
Removing Plastic Trim
........................................... 2-2
Front Panel Controls and Connectors ..............................
3-Q
Effect of External lnput Controls ................................... 3-1
Positioning of Controls
......................................... 3-2
Pulse Output in NORM Mode ..................................... 3-3
Pulse Dutput in External Width Mode ............................... 3-3
PulseGutputinGateMode ....................................... 3-4
Pulse Output in External Trigger Mode
............................... 3-4
Stepped pulse with high-2 output
................................... 3-5
Flip-Ffop Tzsr Circuit ........................................... 3-6
FlipF!op Test Waveforms ....................................... 3-6
NoisePulses ................................................. 3-7
6082A Pulse Generator - Block Diagram ............................. 4-Q
Repetition Rate Generator - Block Diagram ........................... 4-1
Rate Generator ............................................... 4-2
Transition Detector Pulse Output ................................... 4-3
Delay Generator - Block Diagram
................................... 4-4
Slope Generator Diagram and Waveforms .............................. 4-5
Attenuator Element ........................................... 4-6
Input z&age and Attenuator ....................................... 4-7
Attenuator and Gain Control ..................................... 4-8
Connections between Test Box 15265A and 8Q82A
....................... 5-12
location of adjustment controls ................................... 5-25
Mainframe Parts Identification
..................................... 6-2

List of Table
TABlS
TabJe Title
l-1
5-1
5-2
5-3
5-5
5-7
5-9
5-10
5-11
5-l 2
5-13
5-14
5-15
5-16
5-17
5-18
5-19
5-20
5-21
5-22
5-23
5-24
5-25
5-26
5-27
6-l
6-2
6-3
6-4
Specifications
................................................
Test Equipment z . ..’ Accessories for Performance Checks
...................
Performance Check - Repetition Rate
...............................
Performance Check - Delay (Slow) .................................
Performance Check - Width (Slow)
.................................
Performance Check - Jitter .....................................
Performance Check - Width (Fas;j
.................................
Performance Check - Delay (Fast) .................................
Performance Check -SquareWaveDutyCycle
.........................
Performance Check - External Functions .............................
Performance Check - Transition Time
...............................
Performance Check - Preshoot, Overshoot and Ringing
....................
Performance Check - Amplitude ...................................
Performance Check - Check Record
.................................
Summary of adjustable and factoryselected components
...................
Test Equipment and Accessories for Internal Checks and Adjustments
.............
TestandAdjustmentsPerformedbyTestBox 15265A
.....................
Power Supply .................................................
Rep. Rate ...................................................
Delay and Width (Verniers CW)
.....................................
Amplitude, Risetime, Overshoot (Ins - 511s Transition Time)
.................
Amplitude, Risetime, Overshoot (Slower Transition Times)
.................
Pulse Shape and Transition Times
...................................
Positive Pulse Baseline ...........................................
Width .....................................................
Gate ......................................................
Double Pulse .................................................
Safety Check .................................................
Component Designators ..........................................
Manufacturer% Code Numbers end Abbreviations for Parts Lists.
..............
h-ts List ...................................................
Schematic Diagram Notes .........................................
l-2
5-3
5-4
5-4
5-5
5-5
5-6
E-7
5-7
5-8
5-9
5-9
5-19
5-l 1
5-18
5-19
5-29
5-23
5-23
5-24
5-25
5-26
5-26
5-27
5-27
5-27
5-27
5-28
6-l
6-l
6-5
6-13

SAFETY CQMSIDERATlOMS
GENERAL -This is a Safety Class I instrument
(provided with terminal for protective earthing)
and has been manufactured and tested according to
international safety standards.
OPERATION - BEFORE APPLYING POWER
comply with the instalfation section. Additionally,
the following shall be observed:
Any interruption of the protective (ground-
ding) conductor (inside or outside the
instrument) or disconnecting the protective
earth terminal is likely to make this instru-
ment dangerous. tntentionaf interruption is
prohibited.
Whenever it is likely that the protection has
been impaired, the instrument must be made
inoperative and be secxed against any un-
intended operation.
Make sure that only fuses with the required
rated currznt and of the specified type
{normal blow, time deiay, etc.) are used for
replacement. The use of repaired fuses and the
short-circuiting of fuseholders must be
avoided.
Adjustments described in the manual are per-
formed with power supplied to the instrument
while protective covers are remowed. Energy
available at many points may, if contacted,
result in personal injury.
Any adjustment, maintenance, and repair of
the opened instrument under voltage should be
avoided as much as possible, and when inevitable,
should be carried out only by a skilled person
*who is aware of the hazard involved.
SAFETY SYMBl)LS
The apparatus will be marked with this
symbol when it is necessary for the user to
refer to the instruction manual in order to
protect the apparatus against damage.
Indicates dangerous voltages.
Earth terminal {sometimes used in man-
ualto indicated circuit common con-
nected to grounded chassis).
WARNING
The WARNING sign denotes a
hazard. It calls attention to a
procedure, practice or the like, which,
if not correctly performed or adhered
to, could result in injury or loss of tife.
Do not proceed beyond a WARNING
sign until the indicated conditions
are fully understood and met.
CAUTION The CAUTiON sign denotes a hazard.
It calls atkct:!ttion to an operating
procedure, practice, or the like, which,
if not correctly performed or adhered
to, could result in damage to or destruc-
tion of part or all of the equipment.
Do not proceed beyond a CAUTION
sign until the indicated conditions are
fully understood and met.
Capacitors inside the instrument may still be
charged even if the instrument has been :liscon-
netted from its source of supply.

GENERAL INFORMATION
t-1
INTRODUCTliON
1-2 The 8082A is a 250 MHz dual channel pulse
source with variable leading and trailing edge transition
times as fast as Ins. It also has variable pulse frequency,
delay, width, offset and amplitude. The normal/compie-
ment reiationship and the polarity of either output can
be reversed. Single pulse, double pulse and square wave
operatiol) are available. There are also four trigger
modes-
1-3 Norma! Mode. in this mode the 8082A oper-
ates as a self-contained pulse source with f&i control
of the p&e parameters from the front panel controls.
1-4 Ext Trig Mode. in this mode the pulse and
trigger output frequencies are determined by the fre-
quency of an externaity applied signal. The other puke
parameters are varied from the front panei controis.
l-5
Gate Mode. In this mode a gating signal
enables the pulse and trigger outputs.
1-6
External Width Mode. in this mode the pulse
frequency and width are determined by the frequency
and width of an externally applied signal. The delay be
tween input and output is fixed. The trigger output
is the shaped trigger input signal.
1-7
ECL OUTPUT
1-8
The 8082A has an ECL position on each of
its amplitude range switches. When e;ther or both of
the switches are se? to this position, both 8082A outputs
automatically deliver a fixed voltage swing of -0.9V to
-7.7V typical (into an open circuit) for driving ECL
logic.

Table l-7 Specifications
These specifications apply when:
PULSE CHARACTERlSTlCS
Bource and Doad impedance 5052)
Transition Times:< Ins to 0.5ms in
6 ranges. First range from < Ins to
5ns controls ieadingand trailing edges
simuitaneoufsy. For all other ranges
transition timesvariable independent-
ly up to 7:lO.
Difference between risetime and fall-
time is less than 25% of the faster
transition time of the two.
Overshoot and Ringing: & + 5% of
pulse ampiitude may increase to
3~ 10% with amplitude vernier CCW.
Preshoot: < + 5% of pulse amplitude.
Linearity: Linearity aberration for
both slopes < 5% FOF transition times
> 5ns.
Output: Maximum amplitude is 5V
from 5051 into 5OQ. Maximum out-
put voltage is + 5V (amplitude t off-
set).
Offset > Z!T 2V, into 5OG!
Baseline: OV t 150mV with offset
switched off and amplitude range
set to maximum. Other amplitude
ranges reduce baselineproportionately
DCSource Impedance: 5052 T 5% .
Reflection Coefficient Reffection 1s
2% typical for steps with 1 ns rise time
applied to output connector on all
amplitude ranges except 5V range.
On the 5V range, the reflection may
be 15%.
OutPut protection: Cannot be da-
maged by open o; short circuits or
application of ext < It 6 volts or
+ 2QOmA independent of control set -
tings.
Attenuator: Two separate three step-
attenuators reduce the outputs to 4 V.
Vernier is common for both outputs
and reduces the output to 0.4V
minimum. A further position pro-
vldesECL-compatibleoutputsi-O,9V
1) both outputs are
terminated by a 50-Q
load,
TIMING
Repetition Rate: > 250 hri!-!z to
< 1 kHz in 6 ranges.
Period Jitter: < 0.7 % + 50~s
Delay: < 2ns to > 0.5ms in 6 ranges
plus typ. 18ns fxd. with respect to
trigger output.
Delay Jitter:< 0.1% 9 50~s
Double Pulse: Up to 125 MHz max.
(simufatesEXIMHz).Min pulsespacing
2 4ns.
Delay Duty Cycle: > 50%
Pulse Width: < &s to > 0.5ms in 6
ranges.
Width Jitter: < 0.1% + 50~s
Width Duty Cycte: > 50%
Square Wave: A further position of
the Pulse Width switch provides
Square Wave output. (Delay and
double pulse are disabled, max. Rep.
Rate 250 MHz). Duty cycle is 50%
+ 10% up to 100 MHz, 50% + 15%
for > 100 MHz.
Trigger Output: Negative going
Square Wave (50Y3 duty cycle typ.)
> 500mV from 50R Into 5Os1.
Internal 5Ofi ioad can be switched
off by slide-switch on PC-board.
Amplitude increases to 2 1V into
5Cfz up to 200 MHz.
Trigger Output Protection: Cannot
be damaged by short circuit or appli-
cation of externai f 200mA.
EXTERNALLY CONTROLLED
OPERATION
External input
1 npus Impedance: 5Ofi + 10%. DC
coupled.
Maximum input: f 6V
Trigger Level: Adjustable - 1.5V to
2) the internal 5042
source impedance is
selected.
Slope Control: Positive, negative or
manual selectable. In the MAN-posit-
ion all ext. functions can be con-
trolled by push button. Button
pushed in simulates an “on-signal”.
Sensitivity: Sine-wave > 2OOmVpp,
pulses > 2QOmV.
Repetition Rate: 0 to > 250 MHz.
Ext.-Controlled Modes
Ext.frigger: There are approximateiy
7ns delay between the external rnput
and the trigger output. Rep.-Rate is
ext. controlled (is triggered by exter-
nal signal). Trigger output provides
the pulse-shaped input signal. Square
wave mode is disabled.
Synchronous Gating: Gating signal
turns rep. rate generator on. Last
pulse is of normal width even if gate
ends during the pulse.
External Width: Output pulse width
determined by width of drive input.
Rep. Rate and Delay are disabled.
T J igger output provides shaped input
siqnal.
OPTIONS
Option 907 Front Handle Kit
Option 908 Rack Flange Kit
Option 909 Rack Fiange plus Front
Handie Kit
Option 910
Additional Instrument
Manual
GENERAL
Power Requirements: 7 OOV I 12QV,
22OV * 24ov t+5%, - 10%) 48 - 440
Hz. Powt:r consumption 85VA max .
Weight: Nei 7.9 kg 417.44 lhs),
shipping 8.9 kg 119.63 Ibsf.
Dimensions 426mm wide, f45m:m
hi& li8nmm drwn i IG Y/A ;nc v

Figure 2-I. 8082A and Supplied Accessories
Front handle
Order Option 907
Figure 2-2. Avaiiable Accessaries
Rack flange with front handle
Order Option 909 Rack flange
Order Option 908

t
2-I GENERAL
2-2 Initial I nspction
2-3
Inspect the instrument and accessories for
physical damage, and if damage is evident, refer to para-
graph 2-19 for the recommended claim procedure and
repacking information.
2-4
ACCf?SXHkS
2-5
The following accessories are strpptied with
the standard instrument (Figure 2- 1) :
1 A fuse (for 22Clf240V operation)
2A fuse (for 7 lWf20V operation)
Power cord
Operating and Service Manual
HP Part Number
2 110-0007
211 o-0202
see Figure 2-3
For an additional manual. order option 910.
Handles are rack mounting flanges are delivered with the
instrument only if the appropriate option (Figure 2-2)
is ordered
NEMA TYPE
HP Part No. 8120-l 348
I
i
LINE = BLACK
NEUTRAL = WHITE I
GRGUNO =YfLLaNiGAEEN 1
SCHUKO TYPE
HP Part No. 8120- 1689
LINE = BROWN
NEUTRAL = BLUE
GROUND = YELLOW/GREEN
2-6 PowerCords
2-7
The instrument~is :;upplied with one of the
power cords shown in Figure 2--3.
2-8 INSTALLATION
2-9
PowerCord
2-10 The 3wire power cable supplied with the
801 GA, when connected to the appropriate pozver out-
let, grounds the instrument cabinet and paneis. Tc ore
serve this safety feature when operating the instrumer,?
‘ram an outlet without a ground connection, use an
appropriate adapter and connect the ground lead
(green/yellow1 to an external ground.
2-l 1 If the plug on the cable does not fit your
power outlet, then Cut the cable at the plug end and
connect a suitable plug The plug should meet local
safety requirement and include the following features:
a. Minimum current rating of 2A
b. Ground connection
c. Cable clamp
The colour coding used in the cable will depend on the
cable supplied (see Figure 2-Z?.
I
BRITISH STANDARD TYPE
HP Part No. 8720-1351
LINE = BROWPd
NEUTRAL = BLUE
GROUND = YELLOW/GREEN
USED IN ;4USTRACIA
r-
HP Pan !JO. 8120-7369
LINE = BROWN
MEUTRAL = BLUE
GROUND = YELLOW/GREEN

WARNING
t
To avoid the possibility of injury or death, the foliowing
precautions must be foffowed before the instrument is
switche;l on:
a if this instrument is to be energized via an auto-
cransformer for voltage reduction, make sure that the
ground connection is not interrupted.
b. The power cable plug shaff only be inserted into a
socket outlet provided with a protective earth contact
The protective action must not be negated by the use
of an extension cord without a protective conductor
&oundingL
c The safety check (Table 5-27) shall be executed
before connecting the instrument to the supply.
2-13 The instrument will operate from nominaf
ac line 5dq3plies of WOV, 12OV, 22W or 240V (-lo%, +
5%) at 48 Hz to 66 Hz Two switches on the rear panel
allow one of the four voltages to be selected.
1oov 12OV 22ov
24w
Figure Z-4. Switch Settings for the various Norminal
Powerline Voftages
*
Before applying power to the instrument,
check on the rear panel that the switch is
set in accordance with bcal supply condi-
tions
2--i4
follows: To check the power requirements proceed as
a Remove tk fuse and check its value:
for 22OV/24OV operation 1 A
for lOOV/l2OV option 2P
b. Check that the iine sefector switch
positions corresponds to the local suppEy
voltage. If they do not correspond use a
screwdriver to change the switch positions.
c. insert the correct fuse into tha fus&@&r.
d. Connect the power r&e to the rear con-
nector.
2-15
TemperatureRequirements
2-16 The instrument operates within specifi-
cations when the ambient temperature is between BoC
432’F) and .50°C (122OF1. The word generator may be
stored between -4O’C (-40°F) and 75’ (167OF).
2-18 Figure 2-2 shows the possible handlelracrc-
mounting configurations. If handles are fitted and s&se
quentfy need to be removed, the plastic trim must first
be taken off as shown in Figure 2-5.
Lift a corner of the pla5tk trim with a screw-
give a sharp tap in the direction of

2-19 S AMS)REPACKAGING
2-m
ClaimsforDamage
Z-21 If ;rhysical damage is evident or if the instru-
ment does not meet specification when received, notify
the carrier and the nearest Hewlett-Packard blesfervice
Office. The Sates/Service Office wilt arrange for repair or
replacement of the unit without waiting for settlement
of the claim against the carrier.
2-23
If the instrument is to be shipped to a Hew
lett-Packard SeWService Office, attach a tag showing
owner, address, model and serial number, and the repair
required The sriginel shipping carton and packaging
material may be reuseble but the Hewlett-Packard
Sales/Service Office wilD also provide information ancl
mcommendations on materials to be used if the original
pecking is not awaitabie or reusable.

1 RATE switch: for selecting the ranga of the pulse rate.
2 Rate VERNIER: for continuous adjustment of the repetition
rate within the range selected on the RATE switch. Clockwise rotation
increases the pulse period (redwoq the fate).
3PULSE DOUBLE/NORMAL switch: in the DOUBLE PULSE
position the BCtB2A delivers two pulses for every tr@ger pulse - one
pulse in pha+with the trigger owtpwt and one delayed by the amount
set on the PULSE DELAY controls. DOUBLE PULSE is not available
in the EXT WIDTH mode and is automatically inhib@d if selected.
In the NORMAL position, for each trigger pwlse, the 8DB2A delivers
one pwtse which is delayed on the trigger pulse by the amount set on
the PULSE DELAY controfs.
4PULSE DELAY switch: for selecting the range of the pulse de-
lay with respect to the tr&er output in NORM, GATE and EXT
TRIG modes. Has no effect in the EXT WfDTH and SQUARE WAVE
mndes.
5Pulse dday VERNIER: for continuous adjustment of the pulse
delay within the range selected on the PULSE DELAY switch. Clock-
Wise rotation increases the delay.
6EXT INPUT LEVEL control: defines the threshold level of the
EXTERNAL INPUT over a range -1.5V to +1.5V _
7Mode switch: selects either the internal (NORM) mode or one of
three external modes (EXT WIDTH, GATE or EXT TRIG).
8PULSE WIDTH switch: selects the range of the pulse width re-
quired in all modes except EXT WIDTH. When SQUARE WAVE is
selected a square wave output of 59% duty cycle is prodweed. The
frequency of the square wave depends on the PULSE PERIOD setting.
9Pulse width VERNIER: for continwows adjustment of the pulse
width within the range set on the PULSE WIDTH switch.
70 TRANSITION TIME switch: for selecting the range of leading
and trailing edge transition times.
11 LEADING EDGE vernier: for continuous adjustment of the
leading edge transition time within the range selected on the TRANSI-
TION TlNlE switch. On the fastest range this vernier controls both
leading and trailing edges.
92 TRAlllNG EDGE vernier: for continuous adjustment of the
trailing edga transition time within the range selected on the TRAN-
SITION TfME stitch.
13 AMPLITUDE switch: for selecting tha range of the output pulse
amplitwde available at the OUTPUT / OUTPUT connactor. tn the
ECL position the OUTPUT / OUTPUT oonnector delivers pulses of
fixed ampfitwde (-0.9V to -1.7V into an open circuit) and the ampli-
tude vernier and the offset control are disabled.
14 AMPLITUDE switch: for selecti*rg range of the output pulse
amplitude available at the OUTPUT / OUTPUT connector. In the
ECL position the OUTPUT / OUTPUT connector delivers pulses of
fixed amplitude (-CL9V to -1.7V into an open circuit) and the amPh-
twde vernier and the offset control are disabled.
15 Amplitude VERNIER: for continuous adjustment of pulse am-
plitude from both pwlse outputs simultaneowsfy within the ranges
set on the AMPLITUDE switches.
16 OFFSET vernier: for adjustment of the baseline of both output
pulses simultaneously over the range -2V to *2V.
17 OFFSET switch: for enabling/disabling the OFFSET vernier.
In the OFF position the baseline of both outputs is zero wafts.
18 OUTPUT I OUTPUT connector: 8NC connector.
19 NORM / COMPL switch: reverses the dwty cycle of the two
outputs, what was the normal output becomes the complement and
vice versa.
29 NEG/POS switch: determines the polarity of both output pulses.
21 OUTPUT / OUTPUT connector: BNC connector.
22 TRIGGER OUTPUT I-) connector: ENC connecto:, supplies
negative square wave at a rate determined by the setting gf the pulse
period controls. Pulse delay is refered to the negative going edge of
the trigger. In EXT TRIG and EXT WIDTH modes it will deliver a
shaped version of the trigger input. In GATE mode it will deliver
pulses at the rata set on the pulse period controls for as long as the
gate is open.
23 EXT INPUT connector: ENC connector to which trigger pulses
are epplied in the EXT TRtG, GATE and EXT WIDTH modes.
24 SLOPE / POLARITY switch determines whether a rising (POS)
or falling (NEG) signal will trigger or gate the external input on. MAN
position means that the external signal can be simulated by pressing
the MANUAL button.
25 MANUAL button provides a means of initiating a single pulse
(EXT TRIG mode) each time the button is pressed, a train of pulses
(GATE mode) While the button is pressed, or a pulse Whose width
is WJd to the time the button is pressed (EXT WIDTH mode).
28 LINE ON/OFF switch: press-for-on, press-for-off switch.
27 LINE lamp: glows when LINE ON/OFF switch is ON.

REAR PANEL
36 Fuse
30 Linevoltagesektor
See Section2
32 Line connector
INTERNAL (See Figure 6-2)
A331 Trigger output !K&! internalloadon/off.

OPEF?ATlNG INS
3-I
GENERAL
3-2 This section is divided into two parts. The
first part gives scrme general notes on the operation of
the SO82A together with operating instructions for each
of the four operating modes:
NORM operating mode
EXT WfDTH operating mode
GATE operating mode
EXT TRiG operating mode
Full setting-up instructions are given for Normal mode 3-5 The SLOPE/POLARITY switch determines
followed by any changes in control settings required for whether a rising (POS) or falling (MEG) signal will trigger
the other three modes. Stylized waveforms are given for or gate the external input on. Figure 3-2 shows the effects
each mode to show the resultant pulse shapes. For ease of these controls in the External Width mode.
of operation the instructions will refer to Figure 3-1
which shows the controls identified by a reference num-
ber in a circle. The same reference numbers are used in
the text when each control is mentioned.
3-3 The second part of this section gives appli-
cations information.
3-4 EXTERNAL lNPUT
CHARACTERISTICS

3-6 Any external input pulses must have an ampli-
tude of at least 2OOmV peak-to-peak and must be at least
2ns wide at the level at which triggering is to occur.
3-7 If the SLOPE/POLARITY switch is set to
MAN, the external signal can be simulated by pressing
the MANUAL pushbutton. This button provides a means
of initiating a single pulse (EXT TRIG mode) each time
the button is pressed, a train of pulses (GATE mode)
while the button is pressed, or a pulse whose width is equal
to the time the button is pressed (EXT WIDTH mode).
34 SQUARE WAVE OPERATION
3-9 There is a 8quare Wave facility on the 8082A
which produces a square wave output of 50% duty cycle
in NORMAL mode. If Square Wave is selected in Exter-
nal Trigger or External Width modes, the output is a pulse
shaped version of the trigger input (the output waveforms
are the same as for External Width mode, see Figure 3-4).
If Square Wave is selected in Gate mode, the output is a
gated square wave, the repetition rate of which is set up
on the pulse period controls.
3-10
OUTPUT AMPLITUDE CONTROLS
3-11 Vernier
3-12
Because the amplitude vernier is common to
both outputs, the amplitude relationship of one output
totheotheris1:1,7:2or1:5
3-13 ECL Outputs
3-14 To obtain normal and complement ECL com-
patible pulses from the -two outputs, either one or both
amplitude range switches should be set to the ECL posi-
tion. The ECL levels supplied are -0.9V to -1.7V into
an open circuit, i.e. without an external 50 ohm load.
These output levels can be altered by changing the values
of resistors R35 (ECL amplitude) and R60 (ECL-DC off-
set) on board A5 (Amplitude Vernier and DC Qffset
board).
3-15 INCOMPATIBLE CONTROL SETTINGS
3-16
When operating the 8082A, the layout of
the Pulse Period, Delay and Width controls helps to avoid
incompatible settings as shown in Figure 3-3. Generally,
the Pulsa Period control should be farthest right but the
controls can all be in a straight vertical line if the Pulse
Period vernier is more clockwise than the other two ver-
PULSE PERIOD
-1
PULSE WIDTH
I
Figure 3-3. Positioning of Controls
3-17 NORM OPERATJNG MODE
3-l 8 In this mode the 8082A requires no external
trigger signal to produce an output. Pu+e rate, width,
delay, transition times, amplitude and offset are ell ad-
justed by the front panel controls.
3-19 The initial settings (listed below) are given
to obtain a normal pulse waveform (Figure 3-4) for
someone unfamiliar with the operation of the 8082A.
Both pulse outputs and the trigger output should be
connected to a high-frequency oscilloscope using a
50 ohm system. The oscilloscope (an HP 180C main-
frame with 1810A plug-in or similar 1 GHt bandwidth
sampling oscilloscope) should be set with the sweep
time at O.S&cm and with the sensitivity at 2OOmV/cm.
ON
lp-lop
Mid-range
2n--5n
ccw (24
5On-.5p
NQRMAL/DOUBL ULSE switch 3 NORMAL
Mode Switch 0cw
Llqd
TRANSITION TI
LEADING EDGE
TRAILING ED
AMPLITUDE
NORM
5On-.5p
Mid-range
Mid-range
1 B-2.0
t .o-2.0
ccw (1.0)
OFF
NORM
PCS

ov I
I I I
Figure 3-4. Pulse Output in NORM Mode
3-20 EXT W1DTi-i OPERATING MODE
3-21
In External Width mode, the pulse repetition
rate and width are determined by the repetition rate and
width (at the threshold set by the EXT iNPUT LEVEL
control) of an externally applied sign& In EXT WIDTH
mode the PULSE PERIOD controls, the PULSE DELAY
controls, the PULSE WIDTH controis and the DOUSLEI
NORMAL PULSE switch have no effect on the pulse
output. To obtain an output similar to that in Figure
3-5, adjust the controls as shown below. it is assumed
that the controls are already set-up as described above
for a Normal pulse; therefore only the alterations to these
control settings will be given.
a. Set the Mode switch @ to EXT WIDTH.
b. Apply an external trigger to the EXT
INPUT @ . The input should have the
foliowing characteristics:
Pulse shape - sine or square wave
Amplitude - between 2QOmV and CjV
Frequency - 74kHz
c. Set the EXT r’NPUT LEVEL @ control
as required to vary the switching threshold.
d. Set the SLOPE/POLARITY switch as re-
quired to trigger off the- rising iPOSf or failing
(NEG) edge of the trigger.
EXTERNAL
iNPUT
SIG:: -- L
TRIGGER
OUTPUT
PULSE
OUTPUT
TRIGGER
LEVEL
1v
(17tis)
ov

3-22 GATE OPERATING MODE
3-23
in Gate mode the repetition rate is defined
by the rate controls but no output occurs until the wol-
tage of an externally applied signal rises above (SLOPE/
POLARITY switch set to POS) or falls below (SLOPE/
POLARITY switch set to NEG) the level set on the
EXT INPUT LEVEL control. The last pulse of a ‘burst’
is always of correct width even if the gate closes during
the pulse. To obtain an output similar to that in Figure
3-6, adjust the controls as shown below. It is assumed
that the controls are already set-up as described above for
a pulse in External Width mode; therefore only the alter-
ations to these controls settings will be given, Switching
to External Width mode when in Gate mode can be used
to check for correct functioning of the gate signal.
a. Set the Mode switch @ to GATE.
EXTERNAL
INPUT
SIGNAL
TRIGGER
OUTPUT
TRIGGER
LEv\EL
FIXED
-+b-
i
DELAY (17134 +
+‘V VARIABLE
]I
I
Figure 3-6. Pulse Output in Gate Mode .
3-24 EXT TRIG OPERATING MODE
3-25 In External Trigger mode the pulse and trig-
ger repetition rates are determined by the repetition rate
of an externally applied signal. To obtain an output simi-
lar to that in Figure 3-7, adjust the controls as shown
below. It is assumed that the controls are already set-up
as described above for a puise in Gate mode; therefore
only the alterations to these control settings will be given.
a. Set the Mode switch @ to EXT TRIG.
TRIGGER LEVEL
EXTERNAL +0.5-v- - - -
me--
INPUT SIGNAL %V- - - --- ---
TRIGGER
OUTPUT
PULSE
OUTPUT
IV
+ VARIABLE DELAY
ov

3-26
APPLCATlONS NOTES
3-27 The following section indicates some appli-
cations of the 8082A.
3-28
Digital Applications
3-29 The 9082A can be used to test the following
digital integrated circuit {IC) logic families at their normal
operating speeds:
Propagation delay per gate
RTL 12ns - 27ns
DTL 30ns
TTL 12ns
Schottky TTL
3ns
ECL (including MECL iii) Ins - 4ns
For convenience of operation a special ECL output is
available on the 8082A. This means that by simply sett-
ing either amplitude range switch to the ECL position, an
output pulse width a voltage swing of -0.9V to -1.7V
is produced into an open circuit.
When using the 8082A to test any of the above logic
families, particularly the fast MECL lli logic, it is im-
portant to operate with a 50 ohm transmission system.
The coaxial cable does not need to be terminated at the
fC and by a 50 ohm resistor; the internal 50 ohm ter-
mination of the 8082A is of sufficiently high quality to
provide a clean pulse shape in almost all cases (see para-
graph 3-31) without an external termination, even at
the fastest transition times, This has the advantage that
it enables the 50 ohm coaxial cable to be soldered
directly to the pins of the IC under test without requiring
a 50 ohm terminating resistor. it should be noted, how-
ever, that when no external termination is used, no
connections can be made at any intermediate point
along the transmission cable. For example, suppose the
pulse on leaving the 8082A has 2V amplitude across
an effective 25 ohms (50 ohm internal termination in
parallel with 50 ohm cable); when the pulse reaches the
IC its amplitude is doubied to 4V {open end reflection).
This 4V is reflected back along the cable and is absor-
bed by the 50 ohm termination in the 8082A with only
2% typical reflection at amplitudes up to 4V. The effect
of this action is to produce the stepped pulse shown in
-.
-
^
. .
. .
. .
Pulse at the internal
50 ohm load or along
the cable.
ov
---4v
Pulse at the open
end of the coax
cable.
Figure 3-8. Stepped pulse with high-Z output
3-30
If a detailed analysis of IC waveshapes and
timings is to be made, a l GHz sampling oscilloscope
with a high impedance input probe should be used. The
probe should be connected at the IC pin and not at any
intermediate point along the 50 ohm cable.
3-39 If a number of K’s on one PC board are
being driven from one point on the board and the
printed circuit track is more than 10cm long, then an
external 50 ohm resistor at the end of the 50 ohm
system may be required to preserve the clean pulse
shape at the IC input pins.
3-32 One point to remember, particularly when
testing Ins ECL, is the loss of edge speed due to the
coaxial cable. However, the 8082A is fast enough to
accommodate this edge speed degradation without ex-
ceeding the manufacturers specification. A 1.23 metre
cable is available as HP Accessory number 10503A.
3-33 When testing flip-flops (Motorola MC1666
for example), twu pulse generators are required, one to
provide the clock input and one to provide the data in-
put. One pulse generator is run in square wave mode
and the other is run in external trigger and double pulse
mode and is synchronized from the trigger output of the
first pulse generator (Figure 3-9). Allowance must
be made for the differential delay that will occur be-
tween the two ourputs. This is caused by the fact that
there is an extra 7ns delay in the second 8082A t24ns
against 17ns) due to the delay between the trigger input
and the trigger output. To preserve the correct timing
relationship, therefore, between the two sets of pulse
outputs, the data pulse output must be delayed by a
further 7ns. This can be achieved by increasing the length
of the data output transmission cable (delay is about 5ns