The input offset voltage (VIO) is an internally generated voltage and may be considered as a voltage inserted between the two inputs (see Figure 2-6). In addition, it is a differential input voltage resulting from the mismatch of the operational amplifier input stages.
The effect on currents I1 and 12 can be determined by the following equations:
If the input voltage (VI) is zero, the equation is as follows:
The output voltage is the output offset voltage (VOO). The following equation can be used to determine VOO:
The value of the input offset voltage can be found by dividing the output offset voltage by the closed-loop gain.