A low offset instrumentation amplifier for bio­medical applications

In this paper a low power, superior input referred offset Instrumentation amplifier (IA) suitable for biomedical applications has been described. It uses an intermediate buffering transistor between the opamp and common mode to improve the offset. A prototype of 82dB differential gain and 110dB low-frequency CMRRand common mode input range of .5 to 1.1V.A Prototype has been developed in 45nm CMOS technology and simulated with Spectre. Simulation results shows that the 0.5mV offset voltage and 3x improvement compared to the existing architecture. The circuit consumes 6.75uW from 1.5V supply and occupying 0.00325mm
²
silicon area.