A Low-Noise CMOS Readout Circuit at Low Frequency for MEMS Capacitive Accelerometers

摘要：

This paper describes a low-noise CMOS readout circuit for MEMS capacitive accelerometers at low frequency.It cancels the input parasitic capacitance and the offset by a combination of switches. The raised current los of the input differential pair in the first stage helps reduce sharply the total low-frequency noises without increasing the complexity of the proposed circuit. The switched-capacitor low-pass filter with adjustable bandwidth can eliminate noises and interferences outside its bandwidth,and save chip area at low frequency. The simulation result of the proposed circuit shows that an average 60% noise reduction at low frequency has been achieved when the current in the current source of the first stage is six times larger than the original. The root mean square equivalent input noise voltage is about 6.1nV/rtHz@1kHz. The experimental result shows that the capacitance resolution of the whole CMOS readout circuit is 11aF/rtHz@1kHz.

关键词： low-noise CMOS microelectromechanical systems (MEMS) readout circuit accelerometer

作者: Jianghua Chen Xuewen Ni Bangxian Mo

作者单位: EDA Institute,School of Information Science and Engineering,Shandong University,Jinan 250100,P.R.Chi Institute of Mieroelectronics,Peking University,Beijing 100871,P.R.China Institute of Microelectronics,Peking University,Beijing 100871,P.R.China

会议类型: 国际会议

会议名称: 2009 IEEE 8th International Conference on ASIC(第八届IEEE国际专用集成电路大会)

会议地点: 长沙

会议语种:英文

页码: 313-316

在线出版日期: 2009-10-20（万方平台首次上网日期，不代表论文的发表时间）