Title :
Design of Readout Circuits Used for Micro-machined Capacitive Accelerometer
Author :
Liu, Xiaowei ; Zhang, Haifeng ; Li, Guangming ; Chen, Weiping ; Wang, Xilian
Author_Institution :
MEMS Center, Harbin Inst. of Technol.
Abstract :
This paper describes a closed-loop micro-machined accelerometer implemented in a bulk-micromachining technology with integrated CMOS circuit. The operational principle of accelerometer is detailed. We establish a mathematical model of closed-loop system to compare the performance with the open accelerometer. Electrostatic force is served as a negative feedback in closed-loop operating mode to improve the bandwidth, linearity and dynamic range of micro-machined capacitive accelerometer. The noise source affected readout circuit is discussed to optimize circuit structure. The circuit is simulated using Hspice. The result of the circuit simulation shows good sensitivity and low power consumption. The sensor is designed to measure plusmn5g acceleration. Device sensitivity is larger than 15mV/g.
Keywords :
accelerometers; capacitive sensors; circuit simulation; closed loop systems; digital readout; micromachining; microsensors; Hspice; bulk micromachining; capacitive sensing; circuit simulation; closed-loop system; electrostatic force; integrated CMOS circuit; interface circuit; mathematical model; micromachined capacitive accelerometer; readout circuits; Accelerometers; Bandwidth; CMOS technology; Circuit simulation; Electrostatics; Force feedback; Integrated circuit technology; Linearity; Mathematical model; Negative feedback; Accelerometer; CMOS; Capacitive Sensing; Interface circuit; noise;
Conference_Titel :
Nano/Micro Engineered and Molecular Systems, 2007. NEMS '07. 2nd IEEE International Conference on
Conference_Location :
Bangkok
Print_ISBN :
1-4244-0610-2
DOI :
10.1109/NEMS.2007.352076