A 92dB dynamic range sub-μVrms-noise 0.8μW/ch neural-recording ADC array with predictive digital autoranging

Abstract

High-density multi-channel neural recording is critical to driving advances in neuroscience and neuroengineering through increasing the spatial resolution and dynamic range of brain-machine interfaces. Neural-signal-acquisition ICs have conventionally been designed composed of two distinct functional blocks per recording channel: a low-noise amplifier front-end (AFE), and an analog-digital converter (ADC) [1,2]. Hybrid architectures utilizing oversampling ADCs with digital feedback [3-5] have seen recent adoption due to their increased power and area efficiency. Still, input dynamic range (DR) is relatively limited due to aggressive supply voltage scaling and/or kT/C sampling noise. This paper presents a neural-recording ADC chip with 92dB input dynamic range and 0.99μV