System design of a low noise, low offset instrumentation amplifier with chopper stabilization

A low noise, low offset instrumentation amplifier with chopper stabilization is presented. The equivalent input noise and offset is reduced using the technique of chopper stabilization with a chopping frequency of 100 kHz. The channel charge injection is cancelled by the symmetrical circuit topology. With the wide swing bias circuit design, the amplifier achieves a very high power-supply-rejection ratio (PSRR), and it is operated at a single supply voltage of 5 V. The instrumentation amplifier is simulated using TSMC 0.35-mum CMOS technology. It achieves an input-referred noise voltage of 345 nV / radicHz @ about 1 kHz, which is not very good for muV level signal processing because of the large thermal noise parameter of the process model.