Question

Consider the circuit shown below which reduces the impact of the input bias current. If IB1 = IB2 = Input bias current, then determine the value of R3 so that the output voltage (v0) is not impacted by the input bias current.

(a) (R1 R2)/(R1+R2)

(b) (R1 R2)/(R1-R2)

(c) R1-(R1 R2)/(R1+R2)

(d) R2-  (R1 R2)/(R1+R2)

The question was posed to me in my homework.

I would like to ask this question from DC Imperfections in Operational Amplifiers topic in section Operational Amplifiers of Electronic Devices & Circuits

Answer 1

Right choice is (a) (R1 R2)/(R1+R2)

Explanation: This will be possible when R3 has the same value as the net effect of R1 and R2.