User Guide

Chapter 6 Analog behavioral modeling
168
ABM expression parts
The expression parts are shown in Ta b l e 2. These parts can
be customized to perform a variety of functions
depending on your requirements. Each of these parts has
a set of four expression building block properties of the
form:
EXPn
where n = 1, 2, 3, or 4.
During netlist generation, the complete expression is
formed by concatenating the building block expressions
in numeric order, thus defining the transfer function.
Hence, the first expression fragment should be assigned to
the EXP1 property, the second fragment to EXP2, and so
on.
Expression properties can be defined using a combination
of arithmetic operators and input designators. You may
use any of the standard PSpice arithmetic operators (see
Table 9 on page 3-70
) within an expression statement. You
may also use the EXPn properties as variables to represent
nets or constants.
The following examples illustrate a variety of ABM
expression part applications.
Table 2 ABM expression parts
Part Inputs Output
ABM none V
ABM1 1 V
ABM2 2 V
ABM3 3 V
ABM/I none I
ABM1/I 1 I
ABM2/I 2 I
ABM3/I 3 I
Pspug.book Page 168 Wednesday, November 11, 1998 1:14 PM