User Guide

7
-
6 Tutorial: Usin
g
Constrained Optimization (MOS Amplifier)
The Goals and Constraints
The example circuit is set up with predefined goals and
constraints which you can view using the PSpice Optimizer.
To activate the PSpice Optimizer
1
In Schematics, from the Tools menu, select Run Optimizer.
The PSpice Optimizer window shows the three parameters
(W1, L1, and Iref) and the three specifications. Power is
defined as a goal, and gain and bandwidth are defined as
constraints as shown below.
*. Since Power is a goal, constraint type does not apply.
**. Gain is defined as a constraint because circuit gain
must
remain at 20±1.
***. BW is defined as a constraint because the 3 dB bandwidth
must
be at
least 900 kHz or greater.
Settin
g
Power Gain Bandwidth
Name Power Gain BW
Target 1uw 20 1Meg
Range 100uw 2 100k
Constraint Type N/A
*
= target
**
>= target
***
Analysis DC AC AC
Circuit File m2 m2 m2
Evaluate -i(v2)*10v YatX
(v(vout), 1k)
LPBW
(vdb(vout),3)