User`s guide

Worst-Case Analysis 13
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model parameter. If a .PROBE statement is included in the
circuit file, then the results of the nominal and worst-case runs
are saved for viewing with Probe.
An important condition for correct worst-case
anal
y
sis
Worst-case analysis is not an optimization process; it does not
search for the set of parameter values which result in the worst
result. It assumes that the worst case occurs when each
parameter has been either pushed to one of its limits or left at its
nominal value as indicated by the sensitivity analysis. It shows
the true worst-case results when the collating function is
monotonic within all tolerance combinations. Otherwise,
there is no guarantee. Usually you cannot be certain if this
condition is true, but insight into the operation of the circuit may
alert you to possible anomalies.