User Guide

Testin
g
Performance 6
-7
Tweakin
g
Goals and Constraints
The PSpice Optimizer gives you the advantage of doing
something not possible on the bench: changing the performance
results and seeing what parameter values would produce these
results.
To investigate the parameter changes when changing Gain to a
new target value of 10.
1
Make sure that automatic recalculation is selected.
a
From the Options menu, select Recalculate.
b
In the When frame, click Auto.
c
Click OK.
2
Highlight the current value for Gain, and type 10.
3
Press J.
The PSpice Optimizer automatically adjusts the parameters
to satisfy the results, and then updates the results to match.
The result changes from the value you specified to the
nearest value which still satisfies all of the parameter limits.
In this case, the lower limit of the aGain parameter (0.1) is
violated, so the optimizer uses the smallest allowed
parameter value. This gives a value of 10.8 for Gain.
Note
Because the PSpice Optimizer computes
estimates usin
g
the previously calculated
derivatives, results are typically reliable for only
small chan
g
es in parameter values. After
si
g
nificant tweakin
g
, you should resimulate and
recompute the derivatives to see true
performance. See “
Ensuring reliable results when
tweaking values ” on pa
g
e 3-24 .
new
g
oal value
updated parameter
values