8.1 Application Information

The input offset voltage of operational amplifiers (op amps) arises from unavoidable mismatches in the differential input stage of the op-amp circuit caused by mismatched transistor pairs, collector currents, current-gain betas (β), collector or emitter resistors and so forth. The input offset pins allow the designer to adjust for mismatches resulting from external circuitry. These input mismatches can be adjusted by placing resistors or a potentiometer between the inputs as shown in Figure 12. A potentiometer can fine-tune the circuit during testing or for applications which require precision offset control. For more information about designing using the input-offset pins, see Nulling Input Offset Voltage of Operational Amplifiers.

Figure 12. Input Offset Voltage Null Circuit