A 77-dB DR 16-Ch 2nd-order Δ-ΔΣ Neural Recording Chip with 0.0077mm2/Ch

This paper presents a scalable 16-channel neural recording chip enabling simultaneous acquisition of action-potentials (APs), local-field potentials (LFPs), electrode DC offsets (EDOs) and stimulation artifacts (SAs) without saturation. By combining a DC-coupled Δ-ΔΣ architecture with new bootstrapping and chopping schemes, the proposed readout IC achieves an area of 0.0077mm² per channel, an input-referred noise of 5.53±0.36µVrms in the AP band and 2.88±0.18µVrms in the LFP band, a dynamic range (DR) of 77dB, an EDO tolerance of ±70mV and an input impedance of 283MΩ. The chip has been validated in an in vitro setting, demonstrating the capability to record extracellular signals even when using small, high-impedance electrodes. Because of the small area achieved, this architecture can be used to implement ultra-high-density neural probes for large-scale electrophysiology.