User Guide

Chapter 11 Parametric and temperature analysis
276
Figure 69 Current of L1 when R1 is 1.5 ohms.
To run performance analysis
1 From the Trace menu, choose Performance Analysis .
2 Click OK.
PSpice resets the X-axis variable for the graph to be the
parameter that changed between PSpice runs. In the
example, this is the R parameter.
To see the rise time for the current through the inductor
L1, click the Add Trace toolbar button and then enter:
genrise( I(L1) )
Figure 70, shows how the rise time decreases as the
damping resistance increases for the filter.
Another Y axis can be added to the plot for the overshoot
of the current through L1 by selecting Add Y Axis from
the Plot menu. The Y axis is immediately added. Now
click the Add Trace toolbar button and enter:
overshoot( I(L1) )
Figure 70 shows how the overshoot increases with
increasing resistance.
Troubleshooting tip
More than one PSpice run or data section is
required for performance analysis. Because
one data value is derived for each
waveform in a related set of waveforms, at
least two data points are required to
produce a trace.
Use Eval Goal Function (from the Trace
menu) to evaluate a goal function on a
single waveform and produce a single data
point result.
T
h
e genrise an
d
overs
h
oot goa
l
f
unctions
are contained in the file PSPICE.PRB in the
OrCAD directory.
Pspug.book Page 276 Wednesday, November 11, 1998 1:14 PM