User`s guide

PSpice A/D-Equivalent Parts 6
-37
gain has both a real and an imaginary component. The gain and
phase characteristic is the same as that shown for the equivalent
control system part example using the LAPLACE part (see
Figure 6-7 on page 6-19).
For transient analysis, the output is the convolution of the input
waveform with the impulse response of 1/(1+.001·s). The
impulse response is a decaying exponential with a time constant
of 1 millisecond. This means that the output is the “lossy
integral” of the input, where the loss has a time constant of 1
millisecond.
This will produce a PSpice A/D netlist declaration similar to:
ERC 5 0 LAPLACE {V(10)} = {1/(1+.001*s)}
Frequenc
y
Response Tables
(EFREQ and GFREQ)
The EFREQ and GFREQ parts are described by a table of
frequency responses in either the magnitude/phase domain or
complex number domain. The entire table is read in and
converted to magnitude in dB and phase in degrees.
Interpolation is performed between entries. Phase is interpolated
linearly; magnitude is interpolated logarithmically. For
frequencies outside the table’s range, 0 (zero) magnitude is
used.
EFREQ and GFREQ attributes are defined as follows:
EXPR value used for table lookup; defaults to
V(%IN+, %IN-) if left blank.
TABLE series of either (input frequency,
magnitude, phase) triplets, or (input
frequency, real part, imaginary part)
triplets describing a complex value;
defaults to (0,0,0) (1Meg,-10,90) if left
blank.
DELAY group delay increment; defaults to 0 if
left blank.