A $130\mu \mathrm{W}$ Three-Step DT Incremental $\displaystyle \Delta\sum$ ADC Achieving 107.6dB DR and 99.3dB SNDR with Zoom and Extended-Range Counting

This paper presents an incremental $\Delta\Sigma$ ADC (IADC) utilizing a three-step conversion. By combining the zoom-in and extended-range (ER) counting techniques, the IADC significantly reduces the oversampling ratio (OSR) and power consumption of a standard incremental $\Delta\Sigma$ counterpart. Clocked at 512kHz, the prototype IADC achieves a 107.6dB DR, a 104.9dB peak SNR, and a 99.3dB peak SNDR for a conversion rate of 2kS/s while consuming $130{\mu W}$ from a 1.8V supply. This corresponds to a state-of-the-art Schreier FoMDR of 176.5dB.