User`s guide

8 Monte Carlo and Sensitivity/Worst-Case Analyses

PSpice A/D starts as usual by running all of the analyses

enabled in the Analysis Setup dialog with all parameters set to

their nominal values. However, with Monte Carlo enabled, the

DC sweep analysis results are saved for later reference and

comparison.

After the nominal analyses are finished, more of the specified

analysis runs are performed (DC sweep in this example).

Subsequent runs use the same analysis specification as the

nominal with one major exception. Instead of using the

nominal parameter values, the tolerances are applied to set

new parameter values and thus, new component values.

The summary report generated in this example specifies that the

waveform generated from V(OUT1, OUT2) should be the

subject of the collating function YMAX. In each of the last four

runs, the new V(OUT1, OUT2) waveform is compared to the

nominal V(OUT1, OUT2) waveform for the first run,

calculating the maximum deviation in the Y direction (YMAX

collating function). The deviations are printed in order of size

along with their run number (see Figure 13-3).

With the List option enabled, a report is also generated showing

the parameter value used for each device in each run. In this case

(see Figure 13-4), run 3 exhibits the highest deviation.

ure 13-3

Summary of Monte Carlo Runs for example.sch