Title :
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
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;
Conference_Titel :
Electron Devices and Solid-State Circuits (EDSSC), 2011 International Conference of
Conference_Location :
Tianjin
Print_ISBN :
978-1-4577-1998-1
Electronic_ISBN :
Pending
DOI :
10.1109/EDSSC.2011.6117623
