# Input offset voltage

The input offset voltage (${\displaystyle V_{os}}$) is a parameter defining the differential DC voltage required between the inputs of an amplifier, especially an operational amplifier (op-amp), to make the output zero (for voltage amplifiers, 0 volts with respect to ground or between differential outputs, depending on the output type).[1]
Typical values for ${\displaystyle V_{os}}$ are around 1 to 10 mV for cheap commercial-grade op-amp integrated circuits (IC). This can be reduced to several microvolts if nulled using the IC's offset null pins or using higher-quality or laser-trimmed devices. However, the input offset voltage value may drift with temperature or age. Chopper amplifiers actively measure and compensate for the input offset voltage, and may be used when very low offset voltages are required.