Exercise 8.12 A more elaborate opamp circuit schematic

a)

An answer:
The bias current in the three not-labeled NMOS transistors is IBIAS
The bias current in mn1 and n2 is IBIAS∕2
The bias current in the three PMOS transistors is IBIAS∕2
The bias current in Mo1 and Mo2 is (K1 K2)IBIAS.
b)


An answer:
non-inverting: B inverting: A

c)


An answer:
Due to the presence of the finite rds this yields

rout = 1 gm,Mo1

where

gm,Mo1 = K12IBIAS K2

d)


An answer:

K1 = 1 rout2IBIAS K2 = 1 1000 A V 2 = 1mA V 2

e)


An answer:

ix vA−vB = 1 2gm = 1 22K2 1 2IBIAS = 1 2K2 IBIAS

f)


An answer:
iy ix = 2

g)


An answer:
vC iy = rds

h)


An answer:
vout vC = 1

i)


An answer:

av = vout vA − vB = 1 2K2 IBIAS ⋅ 2 ⋅ rds = rdsK2 IBIAS