Open Access

ARTICLE

A Chopper Negative-R Delta-Sigma ADC for Audio MEMS Sensors

Jamel Nebhen^1,*, Pietro M. Ferreira^2,3

1 College of Computer Engineering and Sciences, Prince Sattam bin Abdulaziz University, Alkharj, 11942, Saudi Arabia
2 Université Paris-Saclay, CentraleSupélec, CNRS, Laboratory de Génie Electrique et Electronique de Paris, Gif-sur-Yvette, 91192, France
3 Sorbonne Université, CNRS, Lab. de Génie Electrique et Electronique de Paris, Paris, 75252, France

* Corresponding Author: Jamel Nebhen. Email:

Computer Modeling in Engineering & Sciences 2022, 130(2), 607-631. https://doi.org/10.32604/cmes.2022.016086

Received 05 February 2021; Accepted 08 September 2021; Issue published 13 December 2021

Abstract

This paper presents a proposed low-noise and high-sensitivity Internet of Thing (IoT) system based on an M&NEMS microphone. The IoT device consists of an M&NEMS resistive accelerometer associated with an electronic readout circuit, which is a silicon nanowire and a Continuous-Time (CT) Δ Σ ADC. The first integrator of the Δ Σ ADC is based on a positive feedback DC-gain enhancement two-stage amplifier due to its high linearity and low-noise operations. To mitigate both the offset and 1/f noise, a suggested delay-time chopper negative-R stabilization technique is applied around the first integrator. A 65-nm CMOS process implements the CT Δ Σ ADC. The supply voltage of the CMOS circuit is 1.2-V while 0.96-mW is the power consumption and 0.1-mm² is the silicon area. The M&NEMS microphone and Δ Σ ADC complete circuit are fabricated and measured. Over a working frequency bandwidth of 20-kHz, the measurement results of the proposed IoT system reach a signal to noise ratio (SNR) of 102.8-dB. Moreover, it has a measured dynamic range (DR) of 108-dB and a measured signal to noise and distortion ratio (SNDR) of 101.3-dB.

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Keywords

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