This file is an example of how to code the PMOS, NMOS and
Natural NMOS transistors. D=drain terminal, G=gate, S=source
and B=bulk or substrate. The project uses an N-well process
so the NMOS devices are made in the field. This means that
you can not short the source to the bulk. The bulk must be 
connected to VSS=0V. The PMOS is made in the N-well and the
source can be connected to the bulk. The width=W and length=L
values are just an example, you will have to figure out what
they need to be for your amp. The multiplicity factor M allows
you to multiply the width so that for M1 the total width
that SPICE uses is 50um * 2 = 100um. The area of the drain=AD
the area of the source=AS, the perimeter of the drain=PD and
the perimeter of the source=PS. For this class project we will
make the source and drain areas and perimeters equal.


How to netlist the 3 types of transistors for the 5V process.


M1 D G S B PCH W=50 L=3 M=2 AD=#W*3# AS=AD PD=#W*2+6# PS=PD
M2 D G S B NCH W=30 L=4 M=2 AD=#W*3# AS=AD PD=#W*2+6# PS=PD
M3 D G S B NAT W=60 L=5 M=1 AD=#W*3# AS=AD PD=#W*2+6# PS=PD