This section is designed to highlight one or two features per issue that may be overlooked because they
are not made visually obvious with a toolbar button.
TMAX, TMIN, FMAX, FMIN Analysis Variables
There are four variables available in Micro-Cap that reference the range of the simulation
for either transient or AC analysis. These variables are defined as follows:
TMIN - Starting transient analysis time
TMAX - Ending transient analysis time
FMIN - Starting AC analysis frequency
FMAX - Ending AC analysis frequency
The main use for these variables is to reference them in the X Range expression field in
the Analysis Limits dialog box. For example, when the X Range has been defined as:
TMAX, TMIN
for a transient analysis, the X Range will constantly be scaled to the values in the
Time Range field. If the Time Range field has been set to 10m, when the simulation is
run, TMAX is set to 10m and TMIN is set with the default value of 0. The advantage of
this method is that the X Range will automatically update to any changes made in the
Time Range field, so there isn't a need to have to manually edit the X Range fields each
instance the simulation time is changed. FMAX and FMIN operate in the same manner in AC
analysis by deriving their values from the Frequency Range field.
These variables are easily placed in an X Range field for either transient or AC analysis
by right clicking in the X Range field when in the Analysis Limits dialog box. A left
click on the X Range header will let you place them in for all available waveforms.
These variables are also available for use in the schematic. An NFV function source can
have its VALUE attribute defined as:
5*sin(2*PI*(1/TMAX)*t)
This equation will produce a sine wave with an amplitude of 5 whose period will always be
equivalent to the maximum time value specified in the Time Range field of the Transient
Analysis Limits dialog box.
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