DocumentCode :
2262025
Title :
A micropower differential charge-balancing switched-capacitor front-end for capacitive microaccelerometers
Author :
Kämäräinen, Mika ; Saukoski, Mikko ; Halonen, Kari
Author_Institution :
Electron. Circuit Design Lab., Helsinki Univ. of Technol., Finland
Volume :
3
fYear :
2005
fDate :
28 Aug.-2 Sept. 2005
Abstract :
In this paper, a micropower differential switched-capacitor front-end for capacitive microaccelerometers is presented. The front-end preserves charge balance in the sensor being read, thus avoiding distortion caused by nonlinear electrostatic forces. All signal paths except the one connected to the middle electrode of the sensor are differential, making integration on the same substrate with digital signal processing easier. Transfer function, -3 dB corner frequency and stability conditions are analysed. The effect of finite DC gain of the operational amplifiers is presented. The front-end achieves a 58dB maximum simulated SNR with 1.8 V operating voltage, when sampling four channels in a time-multiplexed fashion with 10 kHz sampling frequency for each channel. The worst case current consumption is 45 μA. A prototype chip was designed and fabricated in a 0.13 μm CMOS process.
Keywords :
CMOS integrated circuits; accelerometers; capacitive sensors; low-power electronics; microsensors; network synthesis; operational amplifiers; switched capacitor networks; transfer functions; 0.13 micron; 1.8 V; 10 kHz; 45 muA; CMOS process; capacitive microaccelerometers; charge balancing; digital signal processing; finite DC gain; micropower differential switched-capacitor front-end; operational amplifiers; signal path; time-multiplexed sampling; transfer functions; Digital signal processing; Electrodes; Electrostatics; Frequency; Nonlinear distortion; Operational amplifiers; Signal processing; Signal sampling; Stability analysis; Transfer functions;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Circuit Theory and Design, 2005. Proceedings of the 2005 European Conference on
Print_ISBN :
0-7803-9066-0
Type :
conf
DOI :
10.1109/ECCTD.2005.1523150
Filename :
1523150
Link To Document :
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