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Model 9650A
Four-Channel Digital Delay Generator
General
The model 9650A is a four channel digital delay/pulse generator. It
produces four adjustable-width output pulses, A, B, C and D, each of which
can be delayed from a reference time pulse output T0 by a predetermined
amount. It also has two additional difference outputs, A.B and C.D,
representing pulses which start on the rising edge of one output and
finish on the rising edge of a second.
The instrument is triggered either by its own internal clock or by an
external trigger and generates a timing pulse, T0, approximately 35 ns
later. This is the time datum to which all other outputs of the unit are
referenced. The four delays are adjustable over the range 0 to 100 ms
with a 10 ps resolution with the output pulse widths (A, B, C and D)
being variable from 30 ns to 1 ms.
Operating modes include ‘Scan’, where continuously increasing delay
times can be generated, and ‘Burst’ which is a special scan mode that
will generate an output burst of pulses. The unit incorporates a 5 × 7
dot matrix alphanumeric display for setup purposes and a power shutdown
memory to retain the current operating parameters. Up to 30 extra setup
routines can also be stored for recall. All parameters are input through
the front panel keys or through the (optional) computer interface.
Software support is available in the form of a LabVIEW driver and the
Acquire™ data acquisition software. The driver and a demonstration
version of the software, DemoAcquire, are available for download from this
site.
The model 9650A is the ideal instrument for delaying trigger signals in
signal recovery applications or for synchronizing multiple laser
experiments where accurate time relationships are essential.
| External
Trigger |
|
|
Type |
0 to 2 MHz. Threshold
variable from -2.8 V to +3.0 V in 200 mV steps,
positive or negative slope. Preset TTL, NIM and ECL switch
selectable |
|
Impedance |
50 W
or 1 MW in parallel with 15 pF |
| Internal
Trigger |
|
|
Type |
Single Shot or 0.001 Hz
to 999 kHz. Three digit resolution from 1 Hz to 999 kHz,
0.001 Hz resolution below 1 Hz |
|
Accuracy |
±0.1 % |
|
Jitter |
< 0.2 % over 90 %
of range |
|
Settling Time |
< 2 seconds over 90 %
of range |
| Triggers
(general) |
External or internal trigger
rate should be < 1/(longest delay + 330 ns + output pulse
width) for delays up to 80 µs and < 1/(longest delay + 500 µs)
for delays longer than 80 µs |
| Trigger
Inhibit |
Rear panel active low TTL
input inhibits internal and external triggers |
| Insertion
Delay |
35 ns typical (from
input trigger to T0) |
| Delays |
|
Four independent delays
adjustable with respect to T0 in the range 0 to 100 ms |
| Internal
Timebase Stability |
±20 ppm (0 to 50 °C) |
| Delay
Accuracy |
(delay) × (timebase
stability) ±0.3 n |
| Jitter |
|
Between the trigger or any
output and the succeeding output < 50 ps + ((1 × 10-8)
× delay) |
| Output
Pulse Widths |
|
|
T0, A, B, C and D |
30 ns to 1 ms
(screwdriver adjustable) |
|
A.B and C.D |
Minimum settable width for
valid output: 5 ns. Pulse starts on rising edge of A (or C) and
stops on rising edge of B (or D), with edges typically 1 ns
later than A (C) and B (D) leading edges when the latter are set to
5 V output. |
| Output
Levels |
|
|
T0, A, B, C and D |
Low impedance outputs which
generate +5 V, +10 V or -0.8 V into 50 W loads,
with higher levels when terminated in higher impedances. Typical
pulse transition times when driving a 50 W load:
+5 V and +10 V : 1 ns/V risetime, 2.5 ns/V
falltime, < 5 % under/overshoot;
-0.8 V : +300 mV undershoot, 200 mV overshoot |
|
A.B and C.D |
Low impedance outputs which
generate TTL levels into low or high impedance loads. Typical pulse
transition times for a 0.7 V to 2.7 V swing:
5 ns risetime, 5 ns falltime for a 50 W
load
3 ns risetime, 4 ns falltime for a 100 W
load |
| Output
Protection |
Outputs are short circuit and
overload protected and limit if the maximum aggregate current of all
outputs averaged over 5 ms exceeds 0.7 A |
| Scan Mode |
|
All four channels scan
simultaneously with the same delay controlled by the following
parameters: |
|
Initial Delay |
0 to 80 µs in 1 ns
steps |
|
Triggers per Delay Step |
1 to 49,999 |
|
Delay Step Size |
0 to 80 µs in 1 ns
steps |
|
Delay Steps per Scan |
1 to 899 subject to the
overall restriction that the max delay in scan mode is 80 µs |
|
Max trigger rate |
6 kHz external or
internal at each delay step; inter-step delay while unit increments
delay setting is typically 20 ms |
| Scan
Inhibit |
Rear panel active low TTL
input inhibits outputs on completion of current scan |
| Burst Mode |
|
Special case of scan mode
where Delay Step Size = 0. Allows the generation of 1 to 49,999
pulses using external or internal triggers at up to 20 kHz. Use
of scan inhibit input and internal triggers allows the unit to
generate "n" pulses on receipt of a single trigger pulse |
| Display |
|
5 × 7 dot-matrix
alphanumeric vacuum fluorescent |
| Setup
Storage |
The model 9650A automatically
stores the current setup when power is removed and restores it when
power is reapplied. Up to 30 additional setups may be saved for
future use |
| Computer
Interface |
The optional RS232 (-/96) or
GPIB (IEEE-488) (-/97) interfaces allow remote setting of the A, B,
C and D channel delays, the internal rate generator, the scan
parameters and both single and repetitive scans to be initiated or
aborted. LabVIEW driver available for download from this site. |
| Options |
9650A/93 |
Rack Mounting Shelf (for one
or two units) |
|
9650A/94 |
5 MHz External Trigger
Option |
|
9650A/96 |
RS232 Serial Interface
(cannot be installed with 9650A/97) |
|
9650A/97 |
GPIB (IEEE-488) Interface
(cannot be installed with 9650A/96) |
|
9650A/98 |
+15 V Outputs
(Increases +10 V output pulse amplitude setting to +15 V) |
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is
a trademark of AMETEK, Inc.