AN-79 IC Preamplifier Challenges Choppers on Drift (Rev. B)

Since the introduction of monolithic IC amplifiers there has been a continual improvement in DC accuracy. Bias currents have been decreased by 5 orders of magnitude over the past 5 years. Low offset voltage drift is also necessary in a high accuracy circuits. This is evidenced by the popularity of low drift amplifier types as well as the requests for selected low-drift op amps. However, until now the chopper stabilized amplifier offered the lowest drift. A new monolithic IC pre-amplifier designed for use with general purpose op amps improves DC accuracy to where the drift is lower than many chopper stabilized amplifiers.