Efficiency-enhanced and high-precision of input common-mode feedback control using OSA–CLS technique.
- Resource Type
- Article
- Authors
- Wang, Yu-Heng; Lai, Xin-Quan; Li, Qin-Qin; Habib, Kashif
- Source
- Electronics Letters (Wiley-Blackwell). 11/26/2020, Vol. 56 Issue 24, p1303-1306. 4p.
- Subject
- *CAPACITIVE sensors
*VOLTAGE control
*OPERATIONAL amplifiers
*CAPACITORS
*APPROXIMATION theory
- Language
- ISSN
- 0013-5194
Efficiency-enhanced and high-precision input common-mode feedback control (ICMFB) is proposed for a fully differential readout circuit of the MEMS capacitive sensor. This ICMFB improves the efficiency and performance of input common-mode voltage control using a smaller feedback capacitor. The noise performance of the readout circuit is improved as a decrease of a feedback capacitor. The correlated level shift (CLS) technique is used to improve the output swing of the amplifier therefore reduce the value of a feedback capacitor. Also, the oversampling successive approximation (OSA) technique is used to improve the accuracy of input common-mode voltage control using a low-gain op-amp. Simulation results show that the input common-mode voltage error decreases to 0.01% when the value of the feedback capacitor is the same as the MEMS sensor. Also, the noise power spectral density of the readout circuit increases by 10 dB. [ABSTRACT FROM AUTHOR]