Avtech AVO-6A1-B User manual

INSTRUCTIONS
MODEL AVO-6A1-B
50 VOLT / 1 AMP
LASER DIODE DRIVER
WITH IEEE 488.2 AND RS-232 CONTROL
SERIAL NUMBER: 138 5
A V T E C H E L E C T R O S Y S T E M S L T D .
N A N O S E C O N D W A V E F O R M E L E C T R O N I C S
S I N C E 1 7 5
[e-mail]
http://www.avtechpulse.com/
Tel: [phone] (USA & Canada) or [phone] (Intl)
Fax: [phone] (USA & Canada) or [phone] (Intl)
BOX 5120, LCD MERIVALE
OTTAWA, CANADA K2C3H5

WARRANTY
Avtech Electrosystems Ltd. warrants products of its manufacture to be free
from defects in material and workmanship under conditions of normal use. If,
within one year after delivery to the original owner, and after prepaid return by
the original owner, this Avtech product is found to be defective, Avtech shall at
its option repair or replace said defective item. This warranty does not apply to
units which have been dissembled, modified or subjected to conditions
exceeding the applicable specifications or ratings. This warranty is the extent of
the obligation assumed by Avtech with respect to this product and no other
warranty or guarantee is either expressed or implied.
TECHNICAL SUPPORT
Phone: [phone] (USA & Canada) or [phone] (International)
Fax: [phone] (USA & Canada) or [phone] (International)
E-mail: [email protected]
World Wide Web: http://www.avtechpulse.com
2

TABLE OF CONTENTS
WARRANTY......................................................................................................................2
TECHNICAL SUPPORT...................................................................................................2
TABLE OF CONTENTS....................................................................................................3
INTRODUCTION...............................................................................................................5
SPECIFICATIONS............................................................................................................6
REGULATORY NOTES....................................................................................................7
FCC PART 18..........................................................................................................................7
EC DECLARATION OF CONFORMITY..................................................................................7
DIRECTIVE 2011/65/EU (RoHS).............................................................................................8
DIRECTIVE 2002/ 6/EC (WEEE)............................................................................................8
FIRMWARE LICENSING.........................................................................................................
INSTALLATION..............................................................................................................10
VISUAL CHECK....................................................................................................................10
POWER RATINGS................................................................................................................10
CONNECTION TO THE POWER SUPPLY...........................................................................10
PROTECTION FROM ELECTRIC SHOCK...........................................................................11
ENVIRONMENTAL CONDITIONS........................................................................................12
LABVIEW DRIVERS..............................................................................................................12
FUSES.............................................................................................................................13
AC FUSE REPLACEMENT...................................................................................................13
DC FUSE REPLACEMENT...................................................................................................14
FUSE RATINGS.................................................................................................................... 14
FRONT PANEL CONTROLS..........................................................................................15
REAR PANEL CONTROLS............................................................................................17
GENERAL INFORMATION............................................................................................19
AMPLITUDE CONTROL.......................................................................................................1
-SMA OPTION.......................................................................................................................20
LENZ’S LAW AND INDUCTIVE VOLTAGE SPIKES............................................................20
BASIC TEST ARRANGEMENT - WITHOUT OUTPUT MODULE.........................................20
BASIC TEST ARRANGEMENT - WITH OUTPUT MODULE................................................21
BASIC PULSE CONTROL....................................................................................................22
TRIGGER MODES................................................................................................................23
GATING MODES...................................................................................................................24
3

OPERATIONAL CHECK.................................................................................................25
PROGRAMMING YOUR PULSE GENERATOR...........................................................29
KEY PROGRAMMING COMMANDS....................................................................................2
ALL PROGRAMMING COMMANDS.....................................................................................30
MECHANICAL INFORMATION......................................................................................32
TOP COVER REMOVAL.......................................................................................................32
RACK MOUNTING................................................................................................................ 32
ELECTROMAGNETIC INTERFERENCE..............................................................................32
MAINTENANCE..............................................................................................................33
REGULAR MAINTENANCE..................................................................................................33
CLEANING............................................................................................................................ 33
WIRING DIAGRAMS.......................................................................................................3
WIRING OF AC POWER.......................................................................................................34
WIRING OF DC POWER.......................................................................................................35
PCB 158R4 - LOW VOLTAGE POWER SUPPLY................................................................36
PCB 235B - HIGH VOLTAGE DC POWER SUPPLY............................................................37
PCB 217A - RELAY DRIVER................................................................................................38
PCB 104F - KEYPAD / DISPLAY BOARD, 1/3.....................................................................3
PCB 104F - KEYPAD / DISPLAY BOARD, 2/3.....................................................................40
PCB 104F - KEYPAD / DISPLAY BOARD, 3/3.....................................................................41
MAIN WIRING....................................................................................................................... 42
PERFORMANCE CHECK SHEET................................................................................. 3
Manual Reference: /fileserver2/officefiles/instructword/avo-6/AVO-6A1-B,ed2.odt.
Last modified July 12, 201 .
Copyright © 201 Avtech Electrosystems Ltd, All Rights Reserved.
4

INTRODUCTION
The AVO-6A1-B is a high performance, GPIB and RS232-equipped instrument capable
of generating up to 1A at repetition rates up to 10 kHz. The pulse width is variable from
50 ns to 5 us. Rise and fall times are fixed at less than 1 ns. The AVO-6A1-B includes
an internal trigger source, but it can also be triggered or gated by an external source. A
front-panel pushbutton can also be used to trigger the instrument.
The AVO-6A1-B features front panel keyboard and adjust knob control of the output
pulse parameters along with a four line by 40-character backlit LCD display of the
output amplitude, pulse width, pulse repetition frequency, and delay. The instrument
includes memory to store up to four complete instrument setups. The operator may use
the front panel or the computer interface to store a complete “snapshot” of all key
instrument settings, and recall this setup at a later time.
The instrument is protected against overload conditions by an automatic control circuit.
An internal power supply monitor removes the power to the output stage for five
seconds if an average power overload exists. After that time, the unit operates normally
for one second, and if the overload condition persists, the power is cut again. This cycle
repeats until the overload is removed.
The AVO-6A1-B consists of two parts, the mainframe and the output module. The
mainframe is a voltage pulser, which generates up to 50V (VOUT).
Instruments with the "-P" model suffix can generate up to +50V, whereas instruments
with the "-N" model suffix can generate up to -50V. Instruments with the "-PN" suffix can
generate both polarities.
The output module contains a 50Ω series resistance, and packaged diodes may be
soldered to the output terminals of this module. The diode load is connected in series
with the internal resistance, so that the current through the diode is normally given by:
IDIODE = (VOUT – VDIODE) / 50Ω
where VDIODE is the voltage drop across the diode.
For chip-level testing, the output module is not used. In this case, a user-supplied
resistance of 50 Ohms should be connected in series with the chip, near the chip, and
the voltage waveform from the mainframe should be connected to the resistor/diode
series combination using coaxial cabling and/or coaxial probes. The resistance must be
capable of dissipating up to 2.5 Watts of average power, if the AVO-6A1-B is to be used
over its full range of capabilities.
This instrument is intended for use in research, development, test and calibration
laboratories by qualified personnel.
5

SPECIFICATIONS
Model: AVO-6A1-B1
Maximum amplitude at
mainframe output (VOUT)2:50V
Current transformer ratio (N): 1
Output impedance (RSERIES): 50Ω, ±10%
Maximum current output8,
(VOUT/N) / RSERIES:1 Amp
Pulse width (FWHM): 50 ns - 5 us
Rise & fall time (20%-80%): ≤ 1 ns
Maximum PRF: 10 kHz
Duty cycle (max): 5 %
Polarity3: Positive or negative or both (specify)
DC offset or bias insertion: Optional4. Apply required DC bias current in the range of ± 100 mA to solder terminals
on the output module. Not available on the AVO-6HF-B, AVO-6HZ-B, or AVO-6C1-B (50 us models).
Propagation delay: ≤ 150 ns (Ext trig in to pulse out)
Jitter: ≤ ± 100 ps ± 0.03% of sync delay (Ext trig in to pulse out)
Trigger modes: Internal trigger, external trigger (TTL-level pulse, > 10 ns, 1 kΩ input impedance),
front-panel “Single Pulse” pushbutton, or single pulse trigger via computer command.
Variable delay: Sync to main output: 0 to ±1.0 seconds, for all trigger modes (including external trigger).
Sync output: > +3 Volts, > 50 ns, will drive 50 Ohm loads
Gate input: Synchronous or asynchronous, active high or low, switchable. Suppresses triggering when active.
Monitor output: Optional5. Provides an attenuated coincident replica of output voltage.
GPIB, RS-232 control2: Standard on -B units.
Ethernet port, for remote
control using VXI-11.3, ssh,
telnet, & web:
Included. Recommended as a modern alternative to GPIB / RS-232.
See http://www.avtechpulse.com/options/vxi for details.
Settings resolution: The resolution of the timing parameters (pulse width, delay, period) varies,
but is always better than 0.15% of (|set value| + 20 ns).
The amplitude resolution is < 0.1% of the maximum amplitude.
Settings accuracy: Typically ± 3% (plus ±1V or ± 3 ns) after 10 minute warmup, at low duty cycles7. For high-accuracy
applications requiring traceable calibration, verify the output parameters with a calibrated oscilloscope.
Output connectors: Standard: Solder terminals (one for OUT, one for GND).
-SMA option: replaces the two solder terminals with a single SMA connector .
Optional output device
sockets:
The standard solder terminals can be replaced by a plug-in or screw-in socket.
See http://www.avtechpulse.com/laser-bias/avx-s1 for examples.
Contact Avtech ([e-mail]) with your special device mounting requirement.
Connectors, other: BNC
Power requirements: 100 - 240 Volts, 50 - 60 Hz
Dimensions:
(H x W x D)
Mainframe: 100mm x 430 mm x 375mm (3. ” x 17” x 14.8”)
Output module: 41 mm x 66 mm x 76 mm (1.6” x 2.6” x 3.0”)
Chassis material: Cast aluminum frame and handles, blue vinyl on aluminum cover plates
Mounting: Any
Temperature range: +5°C to +40°C
1) -B suffix indicates IEEE-488.2 GPIB and RS-232 control of amplitude and frequency. See http://www.avtechpulse.com/gpib/ for details.
2) For operation at amplitudes of less than 20% of full-scale, best results will be obtained by setting the amplitude near full-scale and using external
attenuators on the output (between the mainframe and the output module).
3) Indicate desired polarity by suffixing model number with -P or -N (i.e. positive or negative) or -PN for dual polarity.
4) For DC offset option suffix model number with -OS. Not available for the models AVO-6HF-B, AVO-6HZ-B, or AVO-6C1-B (50 us models).
5) For monitor option add suffix -M.
6) Add the suffix -CLZ to the model number to specify this output arrangement. For the AVO-6D-B only.
7) The amplitude may decrease ~10% relative to the programmed setting if the instrument is operating at or near the maximum specified duty cycle.
8) For VDIODE = 0V.
) This is only suitable for connecting to very short lengths of cable (less than 12 inches or 30 cm), since it is located after the impedance-matching
resistance. Any length of cabling will introduce transmission line reflections due to the impedance mismatch. The cable will act as an inductance. The
load should be located as close as possible to the output connector (regardless of whether solder terminals or the SMA connector is used).
6

REGULATORY NOTES
FCC PART 18
This device complies with part 18 of the FCC rules for non-consumer industrial,
scientific and medical (ISM) equipment.
This instrument is enclosed in a rugged metal chassis and uses a filtered power entry
module (where applicable). The main output signal is provided on a shielded connector
that is intended to be used with shielded coaxial cabling and a shielded load. Under
these conditions, the interference potential of this instrument is low.
If interference is observed, check that appropriate well-shielded cabling is used on the
output connectors. Contact Avtech ([e-mail]) for advice if you are unsure
of the most appropriate cabling. Also, check that your load is adequately shielded. It
may be necessary to enclose the load in a metal enclosure.
If any of the connectors on the instrument are unused, they should be covered with
shielded metal “dust caps” to reduce the interference potential.
This instrument does not normally require regular maintenance to minimize interference
potential. However, if loose hardware or connectors are noted, they should be
tightened. Contact Avtech ([e-mail]) if you require assistance.
EC DECLARATION OF CONFORMITY
We Avtech Electrosystems Ltd.
P.O. Box 5120, LCD Merivale
Ottawa, Ontario
Canada K2C 3H5
declare that this pulse generator meets the intent of Directive 2004/108/EG for
Electromagnetic Compatibility. Compliance pertains to the following specifications as
listed in the official Journal of the European Communities:
EN 50081-1 Emission
EN 50082-1 Immunity
7

and that this pulse generator meets the intent of the Low Voltage Directive 2006/ 5/EC.
Compliance pertains to the following specifications as listed in the official Journal of the
European Communities:
EN 61010-1:2001 Safety requirements for electrical equipment for
measurement, control, and laboratory use
DIRECTIVE 2011/65/EU (RoHS)
We Avtech Electrosystems Ltd.
P.O. Box 5120, LCD Merivale
Ottawa, Ontario
Canada K2C 3H5
declare that, to the best of our knowledge, all electrical and electronic equipment (EEE)
sold by the company are in compliance with Directive 2011/65/EU of the European
Parliament and of the Council of 8 June 2011 on the restriction of the use of certain
hazardous substances in electrical and electronic equipment (also known as “RoHS
Recast”). In addition, this declaration of conformity is issued under the sole
responsibility of Avtech Electrosystems Ltd. Specifically, products manufactured do not
contain the substances listed in the table below in concentrations greater than the listed
maximum value.
Material/Substance Threshold level
Lead (Pb) < 1000 ppm (0.1% by mass)
Mercury (Hg) < 1000 ppm (0.1% by mass)
Hexavalent Chromium (Cr6+) < 1000 ppm (0.1% by mass)
Polybrominated Biphenyls (PBB) < 1000 ppm (0.1% by mass)
Polybrominated Diphenyl ethers (PBDE) < 1000 ppm (0.1% by mass)
Cadmium (Cd) < 100 ppm (0.01% by mass)
Bis(2-ethylhexyl) phthalate (DEHP) < 1000 ppm (0.1% by mass)
Butyl benzyl phthalate (BBP) < 1000 ppm (0.1% by mass)
Dibutyl phthalate (DBP) < 1000 ppm (0.1% by mass)
Diisobutyl phthalate (DIBP) < 1000 ppm (0.1% by mass)
DIRECTIVE 2002/ 6/EC (WEEE)
European customers who have purchased this equipment directly from Avtech will have
completed a “WEEE Responsibility Agreement” form, accepting responsibility for WEEE
compliance (as mandated in Directive 2002/ 6/EC of the European Union and local
8

laws) on behalf of the customer, as provided for under Article of Directive
2002/ 6/EC.
Customers who have purchased Avtech equipment through local representatives
should consult with the representative to determine who has responsibility for WEEE
compliance. Normally, such responsibilities with lie with the representative, unless other
arrangements (under Article ) have been made.
Requirements for WEEE compliance may include registration of products with local
governments, reporting of recycling activities to local governments, and financing of
recycling activities.
FIRMWARE LICENSING
Instruments with firmware versions 5.00 or higher use open-source software internally.
Some of this software requires that the source code be made available to the user as a
condition of its licensing. This source code is available upon request (contact
[email protected]om).
Earlier firmware versions do not contain any open source software.

INSTALLATION
VISUAL CHECK
After unpacking the instrument, examine to ensure that it has not been damaged in
shipment. Visually inspect all connectors, knobs, liquid crystal displays (LCDs), and the
handles. Confirm that a power cord, a GPIB cable, and two instrumentation manuals
(this manual and the “Programming Manual for -B Instruments”) are with the instrument.
Confirm that an output module is supplied, with a length of coaxial cable to connect it to
the mainframe. If the instrument has been damaged, file a claim immediately with the
company that transported the instrument.
POWER RATINGS
This instrument is intended to operate from 100 - 240 V, 50 - 60 Hz.
The maximum power consumption is 57 Watts. Please see the “FUSES” section for
information about the appropriate AC and DC fuses.
This instrument is an “Installation Category II” instrument, intended for operation from a
normal single-phase supply.
CONNECTION TO THE POWER SUPPLY
An IEC-320 three-pronged recessed male socket is provided on the back panel for AC
power connection to the instrument. One end of the detachable power cord that is
supplied with the instrument plugs into this socket. The other end of the detachable
power cord plugs into the local mains supply. Use only the cable supplied with the
instrument. The mains supply must be earthed, and the cord used to connect the
instrument to the mains supply must provide an earth connection. (The supplied cord
does this.)
Warning: Failure to use a grounded outlet may result in injury or death due to
electric shock. This product uses a power cord with a ground connection. It must be
connected to a properly grounded outlet. The instrument chassis is connected to the
ground wire in the power cord.
The table below describes the power cord that is normally supplied with this instrument,
depending on the destination region:
10

Destination Region Description Option Manufacturer Part Number
United Kingdom, Hong Kong,
Singapore, Malaysia
BS 1363,
230V, 50 Hz -AC00 Qualtek 370001-E01
Australia, New Zealand AS 3112:2000,
230-240V, 50 Hz -AC01 Qualtek 374003-A01
Continental Europe, Korea,
Indonesia, Russia
European CEE 7/7
“Schuko” 230V, 50 Hz -AC02 Qualtek 364002-D01
North America, Taiwan NEMA 5-15,
120V, 60 Hz -AC03 Qualtek 312007-01
Switzerland SEV 1011,
230V, 50 Hz -AC06 Qualtek 378001-E01
South Africa, India SABS 164-1,
220-250V, 50 Hz -AC17 Volex 2131H 10 C3
Japan JIS 8303,
100V, 50-60 Hz -AC18 Qualtek 3 7002-01
Israel SI 32,
220V, 50 Hz -AC1 Qualtek 3 8001-01
China GB 1002-1 / 20 -1,
220V, 50 Hz -AC22 Qualtek 3 012-01
PROTECTION FROM ELECTRIC SHOCK
Operators of this instrument must be protected from electric shock at all times. The
owner must ensure that operators are prevented access and/or are insulated from
every connection point. In some cases, connections must be exposed to potential
human contact. Operators must be trained to protect themselves from the risk of electric
shock. This instrument is intended for use by qualified personnel who recognize shock
hazards and are familiar with safety precautions required to avoid possibly injury. In
particular, operators should:
1. Keep exposed high-voltage wiring to an absolute minimum.
2. Wherever possible, use shielded connectors and cabling.
3. Connect and disconnect loads and cables only when the instrument is turned off.
4. Keep in mind that all cables, connectors, oscilloscope probes, and loads must
have an appropriate voltage rating.
5. Do not attempt any repairs on the instrument, beyond the fuse replacement
procedures described in this manual. Contact Avtech technical support (see
page 2 for contact information) if the instrument requires servicing. Service is to
be performed solely by qualified service personnel.
11

ENVIRONMENTAL CONDITIONS
This instrument is intended for use under the following conditions:
1. indoor use;
2. altitude up to 2 000 m;
3. temperature 5 °C to 40 °C;
4. maximum relative humidity 80 % for temperatures up to 31 °C decreasing
linearly to 50 % relative humidity at 40 °C;
5. Mains supply voltage fluctuations up to ±10 % of the nominal voltage;
6. no pollution or only dry, non-conductive pollution.
LABVIEW DRIVERS
A LabVIEW driver for this instrument is available for download on the Avtech web site,
at http://www.avtechpulse.com/labview. A copy is also available in National Instruments'
Instrument Driver Library at http://www.natinst.com/.
12

FUSES
This instrument contains four fuses. All are accessible from the rear-panel. Two protect
the AC prime power input, and two protect the internal DC power supplies. The
locations of the fuses on the rear panel are shown in the figure below:
AC FUSE REPLACEMENT
To physically access the AC fuses, the power cord must be detached from the rear
panel of the instrument. The fuse drawer may then be extracted using a small flat-head
screwdriver, as shown below:
Fuses #1 and #2
(AC fuses)
Fuse #4
( C fuse)
Fuse #3
( C fuse)
13
Fuse
rawer
Pry out the fuse
drawer using a
screwdriver.

DC FUSE REPLACEMENT
The DC fuses may be replaced by inserting the tip of a flat-head screwdriver into the
fuse holder slot, and rotating the slot counter-clockwise. The fuse and its carrier will
then pop out.
FUSE RATINGS
The following table lists the required fuses:
Fuses
Nominal
Mains
Voltage
Rating Case Size
Recommended Replacement Part
Littelfuse Part
Number
Digi-Key Stock
Number
#1, #2 (AC) 100-240V 0.5A, 250V,
Time-Delay 5×20 mm 0218.500HXP F2416-ND
#3 (DC) N/A 1.0A, 250V,
Time-Delay 5×20 mm 0218001.HXP F241 -ND
#4 (DC) N/A 0.8A, 250V,
Time-Delay 5×20 mm 0218.800HXP F2418-ND
The recommended fuse manufacturer is Littelfuse (http://www.littelfuse.com).
Replacement fuses may be easily obtained from Digi-Key (http://www.digikey.com) and
other distributors.
14

FRONT PANEL CONTROLS
1. POWER Switch . This is the main power switch. When turning the instrument on,
there is normally a delay of 10 seconds before anything is shown on the main
display, as the internal operating system boots up.
If the main menu does not appear after 30 seconds, turn off the instrument and
leave it off for at least 60 seconds before applying power again.
2. OVERLOAD Indicator . When the instrument is powered, this indicator is normally
green, indicating normal operation. If this indicator is yellow, an internal automatic
overload protection circuit has been tripped. If the unit is overloaded (by operating
at an exceedingly high duty cycle or by operating into a very low impedance), the
protective circuit will disable the output of the instrument and turn the indicator light
yellow. The light will stay yellow (i.e. output disabled) for about 5 seconds after
which the instrument will attempt to re-enable the output (i.e. light green) for about
1 second. If the overload condition persists, the output will be disabled again (i.e.
light yellow) for another 5 seconds. If the overload condition has been removed, the
instrument will resume normal operation.
This overload indicator may flash yellow briefly at start-up. This is not a cause for
concern.
3. SYNC OUT . This connector supplies a SYNC output that can be used to trigger
other equipment, particularly oscilloscopes. This signal leads (or lags) the main
output by a duration set by the "DELAY" controls and has an approximate
amplitude of +3 Volts to RL > 1kΩ with a pulse width of approximately 100 ns.
4. LIQUID CRYSTAL DISPLAY (LCD) . This LCD is used in conjunction with the
keypad to change the instrument settings. Normally, the main menu is displayed,
which lists the key adjustable parameters and their current values. The
“Programming Manual for -B Instruments” describes the menus and submenus in
detail.
3
45
15
2
1

5. KEYPAD .
Control Name Function
MOVE This moves the arrow pointer on the display.
CHANGE This is used to enter the submenu, or to select the operating
mode, pointed to by the arrow pointer.
×10 If one of the adjustable numeric parameters is displayed, this
increases the setting by a factor of ten.
÷10 If one of the adjustable numeric parameters is displayed, this
decreases the setting by a factor of ten.
+/- If one of the adjustable numeric parameters is displayed, and
this parameter can be both positive or negative, this changes the
sign of the parameter.
EXTRA FINE This changes the step size of the ADJUST knob. In the extra-
fine mode, the step size is twenty times finer than in the normal
mode. This button switches between the two step sizes.
ADJUST This large knob adjusts the value of any displayed numeric
adjustable values, such as frequency, pulse width, etc. The
adjust step size is set by the "EXTRA FINE" button.
When the main menu is displayed, this knob can be used to
move the arrow pointer.
16

REAR PANEL CONTROLS
1. AC POWER INPUT . An IEC-320 C14 three-pronged recessed male socket is
provided on the back panel for AC power connection to the instrument. One end of
the detachable power cord that is supplied with the instrument plugs into this socket.
2. AC FUSE DRAWER . The two fuses that protect the AC input are located in this
drawer. Please see the “FUSES” section of this manual for more information.
3. DC FUSES . These two fuses protect the internal DC power supplies. Please see the
“FUSES” sections of this manual for more information.
4. GATE . This TTL-level (0 and +5V) logic input can be used to gate the triggering of
the instrument. This input can be either active high or active low, depending on the
front panel settings or programming commands. (The instrument triggers normally
when this input is unconnected). When set to active high mode, this input is pulled-
down to ground by a 1 kΩ resistor. When set to active low mode, this input is pulled-
up to +5V by a 1 kΩ resistor.
5. TRIG . This TTL-level (0 and +5V) logic input can be used to trigger the instrument, if
the instrument is set to triggering externally. The instrument triggers on the rising
edge of this input. The input impedance of this input is 1 kΩ. (Depending on the
length of cable attached to this input, and the source driving it, it may be desirable to
add a coaxial 50 Ohm terminator to this input to provide a proper transmission line
termination. The Pasternack (www.pasternack.com) PE6008-50 BNC feed-thru 50
Ohm terminator is suggested for this purpose.)
6. GPIB Connector . A standard GPIB cable can be attached to this connector to allow
the instrument to be computer-controlled. See the “Programming Manual for -B
3
17
2
6
1
45
7
8
OUT
GATE
RS-232
GPIB
TRIG

Instruments” for more details on GPIB control.
7. RS-232 Connector. A standard serial cable with a 25-pin male connector can be
attached to this connector to allow the instrument to be computer-controlled. A user
name (“admin”) and a password (“default”, as shipped from the factory) are required
when logging into a serial terminal session. The internal controller attempts to auto-
sense the parity setting. It may be necessary to send a few return characters before
attempting a login in order to provide enough data to allow this auto-sensing to work.
(A standard Linux “agetty” process is used to implement serial control internally.) See
the “Programming Manual for -B Instruments” for more details on RS-232 control.
8. Network Connector . This Ethernet connector allows the instrument to be remotely
controlled using the VXI-11.3, ssh (secure shell), telnet, and http (web) protocols. See
the “Programming Manual for -B Instruments” for more details.
. OUT CONNECTOR . This SMA connector is connected to the output module, when the
output module is used to drive a diode load. If the output module is not used, this
output will generate up to 50V into a load impedance of 50Ω.
18

GENERAL INFORMATION
AMPLITUDE CONTROL
The AVO-6A1-B consists of two parts, the mainframe and the output module. The
mainframe is a voltage pulser, which generates up to 50V (VOUT).
The output module contains a 50Ω series resistance, and packaged diodes may be
soldered to the output terminals of this module. The diode load is connected in series
with the internal resistance, so that the current through the diode is normally given by:
IDIODE = (VOUT – VDIODE) / 50Ω
where VDIODE is the voltage drop across the diode. These values must be selected such
that IDIODE never exceeds 1A.
The functional equivalent circuit of the output module is shown below:
Output Module Functional Equivalent Circuit
An additional resistance (RMON) can be placed in series with the diode load, for current
monitoring purposes. In this case, the diode current is given by:
IDIODE = (VOUT – VDIODE) / (50Ω + RMON )
Alternatively, a fast current probe may be used to monitor the current waveform.
Factory testing is conducted using an Integrated Sensor Technologies model 711S
current probe (https://www.isensortech.com/).
For chip-level testing, the output module is not used. In this case, a user-supplied
resistance of 50 Ohms should be connected in series with the chip, near the chip, and
the voltage waveform from the mainframe should be connected to the resistor/diode
series combination using coaxial cabling and/or coaxial probes. Care must be taken to
1
450 Ω
50 Ω
DIODE
LOAD
IOUT,
1A MAX.
OUTPUT MODULE
MONITOR
OUTPUT
(-M OPTION)
INPUT FROM
MAINFRAME
(UP TO 50V)

ensure that the resistor do not overheat. The resistance must be capable of dissipating
up to 2.5 Watts of average power, if the AVO-6A1-B is to be used over its full range of
capabilities.
-SMA OPTION
On units with the -SMA option, the standard OUT and GND solder terminals are
replaced with a single SMA female connector (with the OUT signal on the center
conductor, and the connector shield being GND). This is only suitable for connecting to
very short lengths of cable (less than 1 inch or 2.5 cm), since it is located after the
impedance-matching resistance. Any length of cabling will introduce transmission line
reflections due to the impedance mismatch. The cable will act as an inductance. The
load should be located as close as possible to the output connector (regardless of
whether solder terminals or the SMA connector is used).
If the user wishes to solder something close to this connector, the Amphenol 132140
male-SMA-to-solder-cup adapter could be used.
The two SMA connectors on the output module are interchangeable (unless the -M
option has been installed, in which case the connectors will be labeled “IN” and “OUT”).
LENZ’S LAW AND INDUCTIVE VOLTAGE SPIKES
This instrument is designed to pulse resistive and diode loads and will exhibit a large
output spike when used to drive a load with significant inductance (as predicted by
LENZ'S LAW). For this reason the load should be connected to the output using low
inductance leads (as short as possible).
The voltage developed across an inductance L (in Henries), when the current is
changing at a rate given by dILOAD / dt (in Amps/sec), is: VSPIKE = L dILOAD / dt.
BASIC TEST ARRANGEMENT - WITHOUT OUTPUT MODULE
The AVO- A1-B can be tested initially without the supplied output module. If the output
module is not used, the mainframe output generates up to 50 Volts into a 50 Ohm load,
as illustrated below:
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