Exercise 6.8 A transimpedance amplifier


An answer:

H(jω) = vout iin vout = A(v+ − v−) = −Av− v− = (vout − v− R2 − iin) 1 jωC1 = vout − iinR2 1 + jωR2C1 vout = −Avout − iinR2 1 + jωR2C1 vout = AiinR2 1+jωR2C1 1 + A 1+jωR2C1 H(jω) = AR2 1 + jωR2C1 + A = A 1 + A ⋅ R2 1 + jω(R2C1 1+A )

From which is follows that

H(0) = A 1 + A ⋅ R2 ω0 = 1 + A R2C1

The magnitude part of a Bode plot is:

pict