Model 4200A-SCS Parameter Analyzer Reference Manual
Section 5: Pulse measure and pulse generator units
4200A-901-01 Rev. C / February 2017
5-5
Average pulses
For pulse I-V (spot mean), the mean values of two or more pulses are averaged. Think of it as the
"mean of the means."
For waveform capture, each acquired reading is a mean average of the corresponding samples for all
the pulses in the burst.
See
(on page 5-71) for details on the average pulses measure mode
for pulse I-V. For UTM programming, the average pulse measure mode is called spot mean average.
The
(on page 13-108) function is used to select the average acquisition type.
See
(on page 5-73) for details on the average pulses measure mode for
waveform capture. For UTM programming, the average pulses measure mode is called waveform
discrete. The
(on page 13-111) function is used to select the average acquisition
type.
Sample rate
For the PMU, the maximum measurement sampling rate for each A/D test is 200e6 (200 million)
samples per second. However, there is a limit to the number of samples (one million) that can be
acquired per A/D test. When a test is configured to exceed that limit, the sample rate is automatically
lowered when using ITMs so that less than one million samples will be acquired.
Pulse I-V (spot mean)
The maximum number of samples per A/D per test is <1,000,000 (one million). If an ITM is configured
to yield more than one million samples, Clarius automatically lowers the sampling rate. For pulse I-V
(spot mean), typically the sample rate is reduced only if the measure window is wide (due to a wide
pulse width or period) or if the number of pulses is large.
The total number of samples for a test is calculated as follows:
Number of samples = Measure window x Sample rate x Number of pulses x Sweep points x Step
points
Example: Test that uses a single PMU to perform 50 20-step sweeps
Pulse width = ~7 µs
Measure window = 1 µs
Sample rate = 200e6 samples per second
Number of pulses = 50
Number of steps in sweep = 20
The number of samples acquired for the above example is calculated as follows:
Number of samples
= 1 µs x 200e6 x 50 x 20 = 200,000
Because the number of samples is less than the one million sample limit, the sample rate of 200e6
samples per second is used for the above example.
