A Low-Power Low-Noise Dual-Chopper Amplifier for Capacitive CMOS-MEMS Accelerometers

作者：Sun Hongzhi^*; Fang Deyou; Jia Kemiao; Maarouf Fares; Qu Hongwei; Xie Huikai

来源：IEEE Sensors Journal, 2011, 11(4): 925-933.

DOI：10.1109/JSEN.2010.2064296

• Accelerometer
• capacitive sensing
• chopper stabilization
• complementary metal-oxide semiconductor-microelectromechanical systems (CMOS-MEMS)
• dual-chopper amplifier (DCA)
• microelectromechanical systems (MEMS)
• monolithic integration

This paper reports a novel dual-chopper amplifier (DCA) and its application to monolithic complementary metal-oxide semiconductor-microelectromechanical systems accelerometers. The DCA design minimizes the power consumption and noise by chopping the sensing signals at two clocks. The first clock is a high frequency for removing the flicker noise while the second clock is a significantly lower frequency to keep the unit gain bandwidth low. A monolithic three-axis accelerometer integrated with the DCA on the same chip has been successfully fabricated using a post-CMOS micromachining process. The measured noise floors are 40 mu g/root Hz in the x- and y-axis and 130 mu g/root Hz in the z-axis, and the power consumption is about 1 mW per axis.

• 出版日期2011-4