A 0.2V, 7.5 μW, 20 kHz ΣΔ modulator with 69 dB SNR in 90 nm CMOS

This paper presents a frequency-to-digital SigmaDelta modulator designed in a digital 90nm CMOS process, operating with a supply voltage of 0.2 V. For a 7.5 muW power consumption, the SNR is 68.9 dB and the SNDR is 60.3 dB over a 20Hz-20kHz bandwidth. This work shows that the SNR/SNDR performance of this kind of SigmaDelta converter can be adjusted over a wide range, while maintaining a state-of-the-art flgure-of-merit of 82 fJ/conversion.