Exercise 7.1 Stability for a trans impedance amplifier configuration

See the opamp circuit below.

pict

The opamp is almost ideal (rin →∞, tout = 0Ω), but it has a frequency dependent gain according to A(jω) = A0 1+jω∕ω0, with A0 ≫ 1.

a)
Derive an equation for the loop gain of this circuit.


We now define an (angular) frequency ω1 = 1 R2⋅C1

b)
With Ao ≫ 1, is it possible to get a phase margin of 45° if ω0 = ω1?
c)
With Ao ≫ 1, is it possible to get a phase margin of 45° if ω0 ≫ ω1?
d)
With Ao ≫ 1, is it possible to get a phase margin of 45° if ω0 ≪ ω1?
e)
Calculate for one of the cases above where 45° phase margin can be obtained, the corresponding/required ω1. The properties of the opamp are fixed.