Exercise 7.1 Stability for a trans impedance amplifier configuration
See the opamp circuit below.
The opamp is almost ideal (,
), but it has a frequency
dependent gain according to ,
with .
-
a)
- Derive an equation for the loop gain of this circuit.
We now define an (angular) frequency
-
b)
- With ,
is it possible to get a phase margin of
if ?
-
c)
- With ,
is it possible to get a phase margin of
if ?
-
d)
- With ,
is it possible to get a phase margin of
if ?
-
e)
- Calculate for one of the cases above where
phase margin can be obtained, the corresponding/required .
The properties of the opamp are fixed.