An interface circuit for high-accuracy signal processing of differential-capacitance transducers

Author

Mochizuki, Kouji ; Masuda, Takashi ; Watanabe, Kenzo

Author_Institution

Dept. of Electr. Eng., Numazu Coll. of Technol., Hamamatsu, Japan

Volume

47

Issue

4

fYear

1998

fDate

8/1/1998 12:00:00 AM

Firstpage

823

Lastpage

827

Abstract

The architecture is based on the idea that the ratio of one of the transducer capacitances to its total capacitance represents the offset binary equivalent of the physical quantity under measurement. An opamp-based capacitance-to-voltage converter is commonly used for capacitance detection, and an analog-to-digital (A/D) converter is used for the ratiometric operation. Analyses show that the interface can detect a capacitance change as small as 0.01% of the total capacitance. Experimental results are also given to confirm the analyses

Keywords

analogue processing circuits; capacitive sensors; intelligent sensors; A/D converter; capacitance change; capacitance detection; differential-capacitance transducers; high-accuracy signal processing; interface circuit; offset binary equivalent; opamp-based capacitance-to-voltage converter; physical quantity; ratiometric operation; total capacitance; transducer capacitances; Analog circuits; Analog-digital conversion; CMOS integrated circuits; Capacitance measurement; Capacitors; Electrodes; Intelligent sensors; Pressure measurement; Signal processing; Transducers;

fLanguage

English

Journal_Title

Instrumentation and Measurement, IEEE Transactions on

Publisher

ieee

ISSN

0018-9456

Type

jour

DOI

10.1109/19.744628

Filename

744628