A reconfigurable IC for wireless monitoring of chemical or electrical neural activity

A reconfigurable integrated circuit for single-channel wireless monitoring of chemical or electrical neural activity is described. It can perform both amperometry and fast-scan cyclic voltammetry (FSCV) when configured for neurochemical sensing, and can record extracellular action potentials as well as local field potentials (LFPs) when configured for electrophysiological studies. The chip architecture employs a third-order DeltaSigma modulator (DeltaSigmaM) and a frequency-shift-keyed (FSK) transmitter operating near 433 MHz. It also incorporates a programmable arbitrary waveform generator for FSCV measurements. The chip is fabricated using the AMI 0.5 mum 2P/3M n-well CMOS process, and achieves a measured current resolution of 94.1 pA_rms in a 5-kHz bandwidth for 300-V/s FSCV and an input-referred noise voltage of 4.69 muV_rms in a bandwidth of 1.1-5 kHz. The modulator core, FSCV waveform generator, and RF transmitter draw ~28 muA, ~40 muA, and ~400 muA from a 2.5-V power supply, respectively.