18.1 A Fully Dynamic Noise-Shaping SAR ADC Achieving 120dB SNDR and 189dB FoM_s in 1kHz BW

High-resolution ADCs with micro power and kHz-level BW have wide applications in portable instrumentation, implantable devices and smart sensors. To enhance flexibility and improve energy efficiency, many systems require duty-cycled operation and expect power scaling with speed. State-of-the-art high-resolution ADC solutions include DSMs, zoom, SAR and noise-shaping (NS) SAR ADCs. The DSM in [1] achieves a high DR of 136dB but limited THD of -116dB, and it consumes high power due to the 4<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup>-order loop filter. The zoom ADC in [2] combining with a coarse SAR and a fine DSM achieves 119.8dB SNR, but it can only process DC signals. The dynamic zoom ADCs [3]–[5] solve the signal BW issue by updating the reference for DSM, however their energy efficiency is not fully exploited due to over-ranging and low quantization resolution (<5b) limited by DWA. Multi-step SAR ADCs [6], [7] can achieve > 100dB SNDR by employing residue amplification, but the hardware cost required for gain and capacitor calibrations is non-trivial. NS-SAR ADCs [8]–[12] can achieve high energy efficiency by introducing noise shaping capability to SAR ADCs, but their SNDRs are limited to around 90~105dB. Besides, most of the ADCs with> 100dB SNDR rely on static amplifiers, resulting in high static power.