User Guide

Chapter 6 Analog behavioral modeling
160
Integrator and differentiator
The integrator and differentiator parts are described
below.
INTEG
The INTEG part implements a simple integrator. A
current source/capacitor implementation is used to
provide support for setting the initial condition.
DIFFER
The DIFFER part implements a simple differentiator. A
voltage source/capacitor implementation is used. The
DIFFER part provides one input and one output.
Table look-up parts
TABLE and FTABLE parts provide a lookup table that is
used to correlate an input and an output based on a set of
data points. These parts are described below and on the
following pages.
TABLE
The TABLE part allows the response to be defined by a
table of one to five values. Each row contains an input and
a corresponding output value. Linear interpolation is
performed between entries.
For values outside the table’s range, the device’s output is
a constant with a value equal to the entry with the smallest
(or largest) input. This characteristic can be used to
IC initial condition of the integrator output
GAIN gain value
GAIN gain value
ROWn is an (input, output) pair; by default, up to
five triplets are allowed where n=1, 2, 3, 4,
or 5
I
f
more t
h
an
f
ive va
l
ues are require
d
, t
h
e
part can be customized through the part
editor. Insert additional row variables into
the template using the same form as the
first five, and add ROW
n
properties as
needed to the list of properties.
Pspug.book Page 160 Wednesday, November 11, 1998 1:14 PM