A Novel Low-Cost Capacitive-Sensor Int

Abstract

This paper describes the design of a new capacitive sensor interface. The interface is based on the use of a novel type of oscillator whose frequency is insensitive to lowand highfrequency interfering signals by the application of a third order high-pass filter and special dither techniques. The fully integrated 0.7 pm CMOS circuit shows an inaccuracy of less than 100 aF with respect to a 2 pF reference capacitor over a -30" to +70° C temperature range. The applied measurement concept guarantees high stability, high accuracy and a negligible influence of parasitic capacitances without the need for calibration. vt€) Fig. 1. of the connecting cables. Two-port measurement of C,. C,l and C,, model the capacitances

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Cite this paper

@inproceedings{L2004ANL, title={A Novel Low-Cost Capacitive-Sensor Int}, author={Frank M. L and Gerard C. M. Meijer}, year={2004} }