A 0.4mm3 Battery-Less Crystal-Less Neural-Recording SoC Achieving 1.6cm Backscattering Range with 2mm×2mm On-Chip Antenna

We demonstrate an all-integrated battery-less crystal-less neural-recording SoC featuring an overall size of 0.4mm3. A dither-based 3rd-order intermodulation (IM3) technique is proposed to prevent the backscattering signal from the blocker of wireless power transfer (WPT), achieving a communication range of 1.6cm with a 2mm×2mm on-chip antenna. Meanwhile, a 2nd-order intermodulation (IM2) wireless-lock technique realizes low-power crystal-less clock generation. In-vivo testing shows that the neural signals recorded by our chip matches the wired testing waveforms including spikes, and the proposed techniques reduce the power consumption to 53.2μW.