
inductors are uncoupled, that is, when k
c
= 0. When the inductors are perfectly
coupled in the sense of k
c
= 1, Eqn (18.29) indicates that no bridging capacitance is
required to achieve constant input resistance.
Using Eqns (18.29) and (18.30), the small signal voltage transfer function,
A
v
(s) = V
os
/V
s
, can be cast in a useful closed form format. This gain analysis is
facilitated by the fact that Eqns (18.29) and (18.30) imply, Z
l
(s) R
l
in Figure
18.12(b), which implies that the time constant associated with the transconductor
output capacitance, C
o
,issimplyR
l
C
o
. If the inverse of this time constant is
significantly larger than the desired compensate ...