Systematic Approach for the Linearization and Readout of Nonsymmetric Impedance Bridges

Author

De Graaf, Ger ; Wolffenbuttel, Reinoud F.

Author_Institution

Delft Univ. of Technol.

Volume

55

Issue

5

fYear

2006

Firstpage

1566

Lastpage

1572

Abstract

This paper presents a general concept for the linearization of impedance bridges with circuit components changing in only one polarity. A feedback loop using a transadmittance amplifier, which is properly designed and matched to the nominal value of the bridge components, reduces nonlinearity from 9% to 0.4% over plusmn20% of bridge imbalance. The method can be applied for dc or ac bridges, and the linearization can conveniently be integrated with the readout circuit, resulting in a highly linear sensor readout. 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

bridge circuits; differential amplifiers; linearisation techniques; readout electronics; transfer functions; bridge components; bridge imbalance; bridge transfer function; circuit components; feedback loop; hyperbolic transfer function; impedance bridges linearization; linear sensor readout; nonsymmetric impedance bridges; readout circuit; transadmittance amplifier; Arm; Bridge circuits; Differential amplifiers; Error compensation; Feedback loop; Impedance; Operational amplifiers; Transducers; Transfer functions; Voltage; Bridge circuits; differential amplifiers; error compensation; linearization; nonlinearities; operational amplifiers; sensor readout; transducers;

fLanguage

English

Journal_Title

Instrumentation and Measurement, IEEE Transactions on

Publisher

ieee

ISSN

0018-9456

Type

jour

DOI

10.1109/TIM.2006.880318

Filename

1703901