Model 4200A-SCS Parameter Analyzer Reference Manual
Section 13: LPT library function reference
4200A-901-01 Rev. C / February 2017
13-117
Pulsers
4220-PGU
4225-PMU
Pulse mode
Standard
Details
Use this command to set the timing parameters for the test. Pulse width, rise time, fall time, and delay
are individually set for the selected channel. The pulse period setting applies to both channels. See
(on page 5-40) for more information on these pulse parameters.
This command returns errors if there is an invalid setting or combination of settings. The rise time of a
pulse cannot be longer than the pulse width. The minimum time allowed for parameters width, rise,
and fall is 20 ns. The minimum value for delay is 0 ns. When setting timing for a sample (waveform
capture), setting the delay to a small value allows the PMU to better capture the rising edge of the
pulse. This value is sample rate dependent, but for the 200 MSa/s rate, a pulse delay of 20 ns to 100
ns will allow the rising edge of the pulse to be captured.
Another internally enforced limit is the minimum off time. This is calculated as:
minimum off time = period
−
delay
−
width
−
0.5 x (rise + fall)
The minimum off time may not be less than 40 ns. To see the whole pulse transition to high when
capturing waveform data, use a small non-zero value like 10 ns for
pulse_delay
.
When a source timing parameter is already set to step or sweep, the step or sweep parameter
overrides the timing parameter set by this command. For details, see
pulse_step_linear
and
pulse_sweep_linear
.
For example, if the
SWEEP_PERIOD_SP
parameter type is selected for the
pulse_sweep_linear
command, the period values for the sweep override the period setting for this command.
Example
pulse_source_timing(PMU1, 1, 0.02, 0.005, 0.01, 0.001, 0.001);
This example the following pulse source timing settings for the PMU, where:
•
instr_id
= PMU1
•
chan
= 1
•
period
= 0.02 (20 ms)
•
delay
= 0.005 (5 ms)
•
width
= 0.01 (10 ms)
•
rise
= 0.001 (1 ms)
•
fall
= 0.001 (1 ms)
Also see
(on page 13-118)
(on page 13-118)
