- Precision delay generator that can be used to delay
the trigger pulse to form the acceleration pulse in TOF-MS
- Adjustable out pulse width
- Interruptible ramp technique gives microsecond delays with
picosecond jitter
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) |
is
a trademark of AMETEK, Inc.