High-accuracy instrumentation amplifier for low voltage low power CMOS smart sensors

In low voltage low power CMOS systems both the high input offset and noise voltages of MOSFETs and also the moderate gain of op amps limit the accuracy of analog circuits. In this paper we present a new high-accuracy instrumentation amplifier; this circuit topology is the first ever reported "non-autozero" instrumentation amplifier which allows one to compensate, beside the input offset and noise voltages of the op amps, also the finite op amp gain. Furthermore, proper dynamic resistor matching may improve both the accuracy of the closed loop gain and the CMRR.