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This work presents a novel ΣΔ analog-to-digital converter (ADC) architecture for a high-resolution sensor interface. The concept is to reduce the effect of kT/C noise generated by the loop filter by placing the gain stage in front of the loop filter. The proposed architecture effectively reduces the kT/C noise power from the loop filter by as much as the squared gain of the added gain stage. The gain stage greatly relaxes the loop filter's sampling capacitor requirements. The target resolution is 20 bit. The sampling frequency is 512 kHz, and the oversampling ratio (OSR) is only 256 for a target resolution. Therefore, the proposed ΔΣ ADC structure allows for high-resolution ADC design in an environment with a limited OSR. The proposed ADC designed in 65 nm CMOS technology operates at supply voltages of 1.2 V and achieves a peak signal-to-noise ratio (SNR) and Schreier Figure of Merit (FoMs) of 117.7 dB and 180.4 dB, respectively.

A smart mask integrated with a remote, noncontact multiplexed sensor system, or "Lab-on-Mask" (LOM) is designed for monitoring respiratory diseases, such as the COVID-19. This LOM can monitor the heart rate, blood oxygen saturation, blood pressure, and body temperature associated with symptoms of pneumonia caused by coronaviruses in real time. Because of this remote monitoring system, frontline healthcare staff can minimize the exposure they face from close contact with the patients and reduce the risks of being infected., Competing Interests: The authors declare no competing financial interest., (Copyright © 2020 American Chemical Society.)