• Optics and Precision Engineering
  • Vol. 19, Issue 3, 580 (2011)
LIU Xiao-wei*, YIN Liang, LI Hai-tao, and ZHOU Zhi-ping
Author Affiliations
  • [in Chinese]
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    DOI: Cite this Article
    LIU Xiao-wei, YIN Liang, LI Hai-tao, ZHOU Zhi-ping. Full differential CMOS interface circuit for closed-loop capacitive micro-accelerometers[J]. Optics and Precision Engineering, 2011, 19(3): 580 Copy Citation Text show less

    Abstract

    A CMOS full differential interface circuit with low noise and high linearity was presented for closed-loop capacitive micro-accelerometers. Based on switched-capacitor detection, the circuit was designed to improve its linearity by a 0.5 μm n-well CMOS process technology. The simulation result shows that the proposed two-path feedback structure provides a good system linearity of 0.01%. The optimized designed PID controller was added into the system,which decreases the stabilization error effectively, increases the system responding speed by 31%, and the linearity by 66.7%. With a ±5 V supply and a sampling frequency of 64 kHz, the circuit can offer the equivalent input noise in 8 μg·Hz-12, system sensitivity in 1.22 V/g, system linearity in 0.03%, and the work range in ±2 g. These results prove that this circuit is suitable for applications of high performance micro-accelerometers to seism detection, oil exploration,etc.
    LIU Xiao-wei, YIN Liang, LI Hai-tao, ZHOU Zhi-ping. Full differential CMOS interface circuit for closed-loop capacitive micro-accelerometers[J]. Optics and Precision Engineering, 2011, 19(3): 580
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