128-channel fully differential digital neural recording and stimulation interface

Abstract

We present a fully differential 128-channel integrated neural interface. It consists of an array of 8times16 low-power low-noise signal recording and generation channels for electrical neural activity monitoring and stimulation, respectively. The recording channel has two stages of signal amplification and conditioning with a programmable gain of 54 dB to 73 dB, and a fully differential 8-bit column-parallel successive approximation (SAR) analog-to-digital converter (ADC). The design is implemented in a 0.35 mum CMOS technology with the channel pitch of 200 mum. The total measured power consumption of each recording channel including the SAR ADC is 15.5 muW. The measured input referred noise is 6.08 muV <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rms</sub> over a 5 kHz bandwidth.