A Modular 512 Channel Neural Signal Acquisition ASIC for High Density 4096 Channel Electrophysiology

The complexity of information processing in the brain requires development of technologies that can provide spatial and temporal resolution by means of dense electrode arrays paired with high-channel-count signal acquisition electronics. In this work, we present a modular 512-channel neural recording circuit that is scalable to up to 4096 simultaneously recording channels. The neural readout application-specific integrated circuit (ASIC) uses a dense 8.2 mm x 6.8 mm 2D-layout to enable high-channel-count, creating an ultralight 350 mg flexible module. The module can be deployed on headstages for small animals like rodents and songbirds, and can be integrated with a variety of electrode arrays.

The chip was fabricated in a 0.18 μm 1.8-V CMOS technology and dissipates a total of 125 mW. Each DC coupled channel features a gain and bandwidth programmable analog front-end, along with 14b analog-to-digital conversion at speeds up to 30 kS/s. Additionally, each front-end includes programmable electrode plating and electrode impedance measurement capability. We present both standalone and in vivo measurements results, demonstrating readout of spikes and field potentials that are modulated by a sensory input.