Title :
A low-noise charge sensitive amplifier for MEMS capacitive sensors
Author :
Wang, Zhanfei ; Li, Zhihong ; Ni, Xuewen ; Mo, Bangxian
Author_Institution :
Inst. of Microelectron., Peking Univ., Beijing
Abstract :
This paper describes a low-noise charge sensitive amplifier (CSA) for MEMS capacitive sensors which uses a chopper technique to reduce the low-frequency noise and offset. The feedback resistors of the CSA are implemented as a MOS-bipolar pseudo-resistors and an input common-feedback (ICMFB) is designed to prevent large output errors from input common-shift and maintain the op-amp within its input common-mode range. A simulated resolution of 5.8aF (rms) in capacitive change integrated over the signal band is achieved while chopped at 1 MHz
Keywords :
MOSFET; capacitive sensors; choppers (circuits); low noise amplifiers; microsensors; operational amplifiers; 1 MHz; MEMS capacitive sensors; MOS-bipolar pseudoresistors; charge sensitive amplifier; chopper technique; feedback resistors; input common-feedback; low-noise amplifier; op-amp; Capacitance; Capacitive sensors; Choppers; Low pass filters; Low-frequency noise; Low-noise amplifiers; Micromechanical devices; Noise reduction; Operational amplifiers; Output feedback;
Conference_Titel :
Solid-State and Integrated Circuit Technology, 2006. ICSICT '06. 8th International Conference on
Conference_Location :
Shanghai
Print_ISBN :
1-4244-0160-7
Electronic_ISBN :
1-4244-0161-5
DOI :
10.1109/ICSICT.2006.306433
