TY - JOUR
T1 - Voltage Control Ratiometric Readout Technique With Improved Dynamic Range and Power-Efficiency for Open-Loop MEMS Capacitive Accelerometer
AU - Zhong, Longjie
AU - Liu, Shubin
AU - Xu, Donglai
AU - Zhu, Zhangming
PY - 2022/12/1
Y1 - 2022/12/1
N2 - MEMS capacitive accelerometer for the Internet of Things (IoT) applications is designed with open-loop structure rather than closed-loop structure to achieve low power consumption. In the open-loop structure, voltage control readout technique is preferred for low cost. However, the voltage control readout technique suffers from low dynamic range and low power efficiency (in terms of FoM ). In this paper, the voltage control ratiometric (VCR) readout technique is proposed to improve both dynamic range and power efficiency. The VCR readout technique is demonstrated in a readout circuit fabricated in a commercial 0.18um 1.8V/5.0V CMOS process. Compared to the traditional voltage readout circuit fabricated with the same CMOS process and tested with the same sensing element, the VCR readout circuit improves full input signal range by 3.5dB (from ±8g±8g to ±12g±12g ) and the noise floor by 9.5dB (from 804μg/Hz−−−√ to 270μg/Hz−−−√ ). As a result, the dynamic range is improved by 13.0dB (from 44.0dB to 57.0dB ), the FoM1 is improved from 310pJ to 83pJ and the FoM2 is improved from 1977μW⋅μg/Hz to 796μW⋅μg/Hz .
AB - MEMS capacitive accelerometer for the Internet of Things (IoT) applications is designed with open-loop structure rather than closed-loop structure to achieve low power consumption. In the open-loop structure, voltage control readout technique is preferred for low cost. However, the voltage control readout technique suffers from low dynamic range and low power efficiency (in terms of FoM ). In this paper, the voltage control ratiometric (VCR) readout technique is proposed to improve both dynamic range and power efficiency. The VCR readout technique is demonstrated in a readout circuit fabricated in a commercial 0.18um 1.8V/5.0V CMOS process. Compared to the traditional voltage readout circuit fabricated with the same CMOS process and tested with the same sensing element, the VCR readout circuit improves full input signal range by 3.5dB (from ±8g±8g to ±12g±12g ) and the noise floor by 9.5dB (from 804μg/Hz−−−√ to 270μg/Hz−−−√ ). As a result, the dynamic range is improved by 13.0dB (from 44.0dB to 57.0dB ), the FoM1 is improved from 310pJ to 83pJ and the FoM2 is improved from 1977μW⋅μg/Hz to 796μW⋅μg/Hz .
U2 - 10.1109/TCSI.2022.3202786
DO - 10.1109/TCSI.2022.3202786
M3 - Article
VL - 69
SP - 5085
EP - 5095
JO - IEEE Transactions on Circuits and Systems I: Regular Papers
JF - IEEE Transactions on Circuits and Systems I: Regular Papers
SN - 1549-8328
IS - 12
ER -