An 8μW Heterodyning Chopper Amplifier for Direct Extraction of 2μVrms Neuronal Biomarkers

This paper describes a prototype architecture that tracks the power fluctuations in discrete frequency bands for a broad spectrum of neuronal biomarkers. The circuit merges chopper-stabilization with heterodyne signal processing to construct a low-noise amplifier with highly programmable, robust filtering characteristics. It is concluded that in our application, the area and modest noise penalty are offset by the benefit of a well-partitioned analog-to-digital boundary flexible enough to potentially extract a wide spectrum of biomarkers associated with disease.