Low-voltage DDA-based chopper-stabilized amplifier for biosignal processing

Abstract

This dissertation presents a low-voltage chopper-stabilized Differential Difference Amplifier (DDA) instrumentation amplifier. The proposed DDA incorporates feed-forward frequency compensation and a Type II compensator to achieve good bandwidth and phase margin, with an unity gain bandwidth (UGB) of 192.5kHz and a phase margin (PM) of 59.8° at a power consumption of 0.74μW at a 0.5V supply. Moreover, the DDA allows the amplifier to attain a high common-mode rejection ratio (CMRR) of up to 100 dB. The integration of chopper stabilization technology further enhances the amplifier's performance by effectively mitigating the offset and 1/f noise. The input noise is 245.5 nV Hz at 1kHz, and the input-referred offset under Monte-Carlo cases is only 0.264mV. The 40 nm CMOS technology provided by TSMC is employed and the simulations is conducted in the Cadence environment. The simulation results have confirmed that the instrumentation amplifier’s low power consumption, minimal noise, and a high common-mode rejection ratio, making it well-suited for the precise processing of biosignals and other analog signal-processing applications.