A 58-dB SNDR 1.32-mW chopper-stabilized analog front-end for graphene hall element detecting application

Recently the new nanoscale material graphene has been widely researched. In this paper a novel chopper-stabilized analog front-end (AFE) is proposed for graphene hall element (GHE) detecting. Consisting of chopper programmable gain amplifier (CPGA) and chopper 2^nd Sigma-Delta modulator (CSDM), the AFE achieves excellent noise performance and large output dynamic range. Implemented with 0.18μm 1P6M mixed-signal technology the AFE occupies active area of 1.84mm². In 3.3V power supply and 50Hz bandwidth, the experiment results indicate typical Signal to Noise and Distortion Ratio (SNDR) is 58.4dB and Effective Number of Bits (ENOB) is 9.4bits. The detecting resolution reaches 4.4×10-5T with total 1.32mW power consumption.