A systematic approach for sensor bridge linearisation and readout

Author

de Graaf, G. ; Wolffenbuttel, R.F.

Author_Institution

DIMES, Delft Univ. of Technol., Netherlands

Volume

2

fYear

2004

fDate

18-20 May 2004

Firstpage

1551

Abstract

A general concept for the linearisation of impedance bridges with circuit components changing in only one polarity is presented. The method can be applied for DC or AC bridges and the linearisation can conveniently be integrated with the readout circuit, resulting in a highly linear sensor readout. A feedback-loop using a trans-admittance amplifier, properly designed and matched to the nominal value of the bridge components, reduces non-linearity from 9% to 0.4% over ±20% of bridge imbalance. In addition to the linearization of the bridge transfer function itself, the method can be applied for the linearization of a range of transducers with a hyperbolic transfer function.

Keywords

CMOS analogue integrated circuits; bridge circuits; circuit feedback; compensation; differential amplifiers; linearisation techniques; transfer functions; AC bridges; CMOS amplifier; DC bridges; OFA; bridge compensation; bridge imbalance; bridge transfer function; differential voltage-to-current amplifier; feedback-loop; hyperbolic transfer function; impedance bridges; sensor bridge linearisation; sensor bridge readout; trans-admittance amplifier; transducer bridge; Arm; Bridge circuits; Impedance; Power supplies; Sensor systems; Temperature dependence; Temperature sensors; Transducers; Transfer functions; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

Instrumentation and Measurement Technology Conference, 2004. IMTC 04. Proceedings of the 21st IEEE

ISSN

1091-5281

Print_ISBN

0-7803-8248-X

Type

conf

DOI

10.1109/IMTC.2004.1351361

Filename

1351361