Question

Find out the input offset current from the circuit

(a) Iio = |IBA*IBC|

(b) Iio = |IBA+ IBC|

(c) Iio = |IBA/ IBC|

(d) Iio = |IBA– IBC|

This question was addressed to me by my college professor while I was bunking the class.

My question is taken from Input Offset Current and Total Output Offset Voltage topic in section Operational Amplifier Fundamentals of Linear Integrated Circuits

Answer 1

The input offset current is the difference between the input bias currents at the two input terminals of an op-amp.

Iio = |IB+ - IB-|

Where:

Iio = Input offset current

IB+ = Bias current at non-inverting terminal

IB- = Bias current at inverting terminal

From the given options, the correct formula is option (b): Iio = |IBA+ IBC|

Formula