A 97dB-PSRR 178.4dB-FOMDR Calibration-Free $\text{VCO}-\mathrm{\Delta\Sigma}$ ADC Using a PVT-Insensitive Frequency-Locked Differential Regulation Scheme for Multi-Channel ExG Acquisition

This paper proposes a 97dB-PSRR, 178.4dB-FOMDR calibration-free 16-channel $\text{VCO}-\Delta\Sigma$ ADC system using a PVT-insensitive frequency-locked differential regulation (FLDR) scheme suitable for wireless ExG Acquisition. Thanks to the FLDR, the SNDR degradation in all 16 channels is less than 1dB over 1.4-2V supply and 20-60°C temperature ranges. Implemented in a $0.18\mu\mathrm{m}$ standard CMOS process, the proposed system consumes $172\mu\mathrm{W}$ from a 1.4V supply and occupies 2.7mm² active area, while a single channel consumes $4.2\mu\mathrm{W}$ and 0.12mm2, respectively.