User Guide

7
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4 Tutorial: Usin
g
Constrained Optimization (MOS Amplifier)
PSpice Optimizer parameters
For optimization, the
parameters for the amplifier are set up using the OPTPARAM
symbol as follows:
The Evaluations
The amplifier is set up with three performance characteristics:
power, gain, and 3 dB bandwidth. To measure performance, the
PSpice Optimizer needs to know how to calculate response for
each of these.
Power
The objective, to minimize power consumption, is a
single-point goal. This means that a trace function appropriately
measures the power response of the circuit.
The amplifier design is set up to measure power by performing
a single-point DC analysis and then applying the trace function
-I(V2)*10V
to the simulation results.
Property Parameters
W1 L1 Iref
Initial Value
75u 5u 100uA
Current Value
75u 5u 100uA
Lower Limit
10u 2u 10uA
Upper Limit
150u 50u 500uA
Tolerance
00
0
To display the Optimizer
Parameters dialo
g
box, double-
click the OPTPARAM symbol in
the schematic.
To see the setup for the
analyses:
1
In Schematics, from the
Analysis menu, select Setup.
2
Click either the DC Sweep or
AC Sweep button to browse
the detail.
3
Click Cancel to return to the
Analysis Setup dialo
g
box.