A Compact Low-Offset Instrumentation Amplifier with Wide Input and Output Ranges

摘要

In this work, a new architecture for the design of very compact instrumentation amplifiers is proposed. The amplifier has been specifically developed for use as a versatile block for sensor interfacing. The most innovative feature of the proposed cell is the wide input common mode range, which has a margin to both power rails as small as 200 mV. The circuit, which has been implemented with the 3.3 V CMOS devices of the UMC 0.18 μm process, operates with supply voltage in the 1.4-3.6 V range. An input offset voltage standard deviation of 8 μV has been obtained using chopper modulation combined with gain enhancement of the output current mirrors. The amplifier performances are estimated by means of accurate electrical simulations.