Analog and mixed signal design: Opamp offset voltage

The DC offset voltage of a differential amplifier is an important parameter for most opamp applications. It also impacts the CMRR of the opamp. In most cases for simple applications the offset voltage of a simple opamp may be perfectly satisfactory. 1 - 5 mV for bipolar designs , 20mV to a 100 mV for CMOS designs. However, when the application is more stringent, very much lower offset voltages are required. In this case special techniques to reduce the offset voltage of the differential amplifier are used. A recent brief article about DC offset voltages released by Signal Processing Group Inc., is available for review in the "Engineer's corner" located in the the SPG website at http://www.signalpro.biz. For further help please contact Signal Processing Group Inc., directly at spg@signalpro.biz.