A 768-Channel CMOS Microelectrode Array With Angle Sensitive Pixels for Neuronal Recording

This paper presents a CMOS sensor array with a 768 low-noise recording sites for neural recording with 2048 intercalated angle-sensitive pixels for optical read-out. The array is highly scalable because of electrode-level digitization with serial data stream-out. The front-end amplifiers use chopping to reduce flicker noise and achieve an input-referred noise of 4.1 μVrms over a 3.6 kHz bandwidth while occupying an area of only 800 μm². Digitization is performed using a distributed ramp ADC that samples every sensor site at 10 kHz. The electrodes have a 50 μm pitch and are plated with platinum to increase the interface capacitance and ensure biocompatibility. The sensor array is used to refocus a lenless image and to record neural spiking and local field potentials from a mouse olfactory bulb slice.