A scalable, highly-multiplexed delta-encoded digital feedback ECoG recording amplifier with common and differential-mode artifact suppression

We present a scalable, highly multiplexed CMOS electro-cortocography (ECoG) recording front-end capable of differential-mode and common-mode artifact suppression. The front-end digitally delta-encodes 8-bit data converters to achieve 14-bit resolution. A single, shared mixed-signal front-end is time-division multiplexed to 64 differential input channels; this reduces channel area by 10x compared to the state-of-the-art. A return-to-zero scheme effectively eliminates channel crosstalk. We present performance and in-vivo measurement results of a 65nm CMOS test-chip implementation of the proposed architecture.