A 0.6-V 86.5-dB DR 40-kHz BW Inverter-Based Continuous-Time Delta–Sigma Modulator With PVT-Robust Body-Biasing

This letter presents a low-power continuous-time delta–sigma modulator (CTDSM) that operates at a 0.6-V supply. The loop filter of the CTDSM is realized with inverter-based integrators and negative-R compensation on each integrator’s virtual ground. A body-biasing technique is used for inverters as well as for negative-Rs to ensure robustness against process, voltage, and temperature (PVT) variations. A prototype CTDSM is fabricated in a 28-nm CMOS process and achieves 83-dB SNDR, 84-dB SNR, and 86.5-dB DR in a 40-kHz bandwidth while consuming only 33.6
$\mu \text{W}$
from a 0.6-V supply. This corresponds to the state-of-the-art Schreier FoM of 177.3 dB.