User`s guide

Parametric Analysis 12
-9
Displa
y
in
g
results in Probe
Use Probe to display the capacitance calculated at the frequency
of interest vs. the stepped parameter.
After analyzing the circuit with PSpice A/D:
1
Run Probe.
2
Load all AC analysis sections.
3
Select Add from the Trace menu.
4
Add the following trace expression:
IMG(-I(Vin)/V(1,0))/(2*3.1416*Frequency)
Or add the expression:
CvF(-I(Vin)/V(1,0))
Where CvF is a macro which measures the effective capacitance
in a complex conductance. Macros are defined using Macro on
the Trace menu. The CvF macro should be defined as:
CvF(G)= IMG(G)/(2*3.1416*Frequency)
Note that -I(Vin)/V(1) is the complex admittance of the R-C
branch; the minus sign is required for correct polarity.
To use performance anal
y
sis to plot capacitance
vs. bias volta
g
e
1
In Probe, select Performance Analysis from the Trace menu.
2
Click Wizard.
3
Click Next>.
4
Click YatX in the Choose a Goal Function list, and then
click Next>.
5
In the Name of Trace text box, type the following:
CvF(-I(Vin)/V(1))