A relaxation-oscillator-based interface for high-accuracy ratiometric signal processing of differential-capacitance transducers

Author

Mochizuki, Kouji ; Watanabe, K. ; Masuda, Takashi ; Katsura, Motoyasu

Author_Institution

Numazu Coll. of Technol., Japan

Volume

2

fYear

1997

fDate

19-21 May 1997

Firstpage

1164

Abstract

For high-accuracy signal processing of differential-capacitance transducers, an interface circuitry is developed based on a relaxation oscillator. Two capacitors of the transducer are multiplexed by diode switches to form the op-amp-based integrator. The duty ratio of the oscillator output then measures the ratio of two capacitances. A circuit analysis shows that the interface can detect the capacitance change as small as 0.01% of the total capacitance. Experimental results are also given to confirm the analysis

Keywords

capacitance measurement; integrating circuits; network analysis; operational amplifiers; relaxation oscillators; signal processing; signal processing equipment; circuit analysis; differential-capacitance transducers; diode switches; duty ratio; high-accuracy ratiometric signal processing; high-accuracy signal processing; interface; interface circuitry; operational amplifier based integrator; relaxation oscillator; relaxation-oscillator; Capacitance measurement; Capacitors; Circuit analysis; Diodes; Integrated circuit measurements; Operational amplifiers; Oscillators; Signal processing; Switches; Transducers;

fLanguage

English

Publisher

ieee

Conference_Titel

Instrumentation and Measurement Technology Conference, 1997. IMTC/97. Proceedings. Sensing, Processing, Networking., IEEE

Conference_Location

Ottawa, Ont.

ISSN

1091-5281

Print_ISBN

0-7803-3747-6

Type

conf

DOI

10.1109/IMTC.1997.612383

Filename

612383