User Guide

Chapter 8 DC analyses
226
Overview of small-signal DC transfer
The small-signal DC transfer analysis calculates the
small-signal transfer function by transforming the circuit
around the bias point and treating it as a linear circuit .
The small-signal gain, input resistance, and output
resistance are calculated and reported.
For N and O devices in the analog interface subcircuits,
has a well-defined linear equivalent.
To calculate the small-signal gain, input resistance, and output
resistance
1 In the Bias Point dialog box, select Calculate
small-signal DC gain (.TF).
2 Specify the value for either an output voltage or the
current through a voltage source in the To Output
variable box.
For example, entering V(a,b) as the output variable
specifies that the output variable is the output voltage
between two nets, a and b. Entering I(VDRIV) as the
output variable specifies that the output variable is the
current through a voltage source VDRIV.
Pspug.book Page 226 Wednesday, November 11, 1998 1:14 PM