5.5 Voltage Offset

As mentioned earlier: the objective of the operational amplifier is to null the difference between its inputs to zero. However, due to the non-ideal properties in the operational amplifier, there is a slight voltage offset that is effectively added in series with the non-inverting input, as shown in Figure 5-3.

In many cases, this small input offset voltage is negligible or can be calibrated out. However, the gain of the operational amplifier will magnify the input offset as an unwanted component of the output. The gain as seen by the input offset voltage is referred to as the Noise Gain (NG), see Signal Gain and Noise Gain for more information.