Capacitor mismatch auto-compensation for MEMS gyroscope differential capacitive sensing circuit

Author

Fang, Ran ; Lu, Wengao ; Wang, Guannan ; Tao, Tingting ; Zhang, Yacong ; Chen, Zhongjian ; Yu, Dunshan

Author_Institution

Dept. of Microelectron., Peking Univ., Beijing, China

fYear

2011

fDate

17-18 Nov. 2011

Firstpage

1

Lastpage

2

Abstract

A capacitor mismatch auto-compensation circuit has been designed and implemented for MEMS gyroscope differential capacitive sensing circuit. An in-chip capacitor array that controlled by the 7-bit SAR is selected to be connected in parallel with one of the gyroscope capacitor, making the two differential capacitors of the gyroscope equal. The compensation progress only takes eight periods of the clock at the start and will be turned off afterward automatically. The chip is fabricated in a 0.35um CMOS process. The test of the chip is performed with a vibratory gyroscope on the condition of a closed-loop control in the drive mode, and the measurement shows that the minimum capacitive compensation is 3.5fF.

Keywords

CMOS integrated circuits; capacitive sensors; capacitors; microsensors; CMOS process; MEMS gyroscope differential capacitive sensing circuit; SAR; capacitor mismatch autocompensation circuit; closed-loop control; differential capacitors; in-chip capacitor array; size 0.35 mum; vibratory gyroscope; word length 7 bit; Application specific integrated circuits; Arrays; Capacitors; Gyroscopes; Micromechanical devices; Sensors; Simulation; Capacitive Sensing Circuit; Capacitor mismatch compensation; MEMS gyroscope; SAR;

fLanguage

English

Publisher

ieee

Conference_Titel

Electron Devices and Solid-State Circuits (EDSSC), 2011 International Conference of

Conference_Location

Tianjin

ISSN

Pending

Print_ISBN

978-1-4577-1998-1

Electronic_ISBN

Pending

Type

conf

DOI

10.1109/EDSSC.2011.6117623

Filename

6117623