Design of a high precision operational amplifier using ping pong auto zero architecture

Abstract

A wide variety of electronic applications deal with small signal inputs. These systems need to have very low offset as well as very low offset drift over time and temperature. High precision is required in these fields. Such fields like instrumentation, automotive and industrial applications require precision amplifiers within reasonable cost and simplicity. The amplifiers by far having the lowest possible offset and offset drift is the auto zero amplifier. In this thesis we describe a precision opamp using ping pong auto zero architecture , which is capable of very low offset and offset drift over temperature along with producing continuous output. The architecture has been designed to operate in extreme environments under a wide temperature. The simulated results show that the amplifier is fully functional and capable of less than 15uV of input referred offset voltage. The design has been carried out in cadence 0.18um technology. It consumes 4.2mW of power and has a offset drift over temperature 3.5uV/0C.