Title :
A low-noise interface for MEMS vibration gyroscope based on a novel power-efficient C/V conversion structure
Author :
Hai Chu ; Wengao Lu ; Liu, M.X. ; Meng Zhao ; Li, X.L. ; Dahe Liu ; Zhang, L.Y. ; Zhongjian Chen ; Yacong Zhang
Author_Institution :
Nat. Key Lab. of Sci. & Technol. on Micro/Nano Fabrication, Peking Univ., Beijing, China
Abstract :
A low-noise MEMS vibration gyroscope interface is presented in this paper. A novel capacitance to voltage (C/V) conversion structure is introduced, which consists of a fully differential capacitor bridge and an active filtering net. An auto-calibration method is proposed, which can compensate the gyroscope mismatch to less than 2fF. We use a multistage noise shaping (mash) sigma-delta modulator to convert the analog signal to bit stream. The input referred noise of C/V conversion stage is 0.63 aF/√Hz at 8 kHz in simulation. The chip converts sensor output into bit stream with 106dB dynamic range.
Keywords :
active filters; bridge circuits; calibration; capacitance measurement; capacitive sensors; capacitors; gyroscopes; microsensors; sigma-delta modulation; vibration measurement; voltage measurement; C-V conversion structure; active filtering net; autocalibration method; capacitance to voltage conversion structure; compensation; frequency 8 kHz; fully differential capacitor bridge; gain 106 dB; low-noise MEMS vibration gyroscope interface; multistage noise shaping sigma-delta modulator; power-efficient C-V conversion structure; Calibration; Capacitors; Filtering; Gyroscopes; Micromechanical devices; Modulation; Noise; capacitor bridge; gyroscope interface; low noise; sigma-delta modulation;
Conference_Titel :
Circuits and Systems (ISCAS), 2015 IEEE International Symposium on
Conference_Location :
Lisbon
DOI :
10.1109/ISCAS.2015.7168723
