Offset-voltage compensation for accurate current-source circuit

Author

Jang, K. ; Lee, Sang-Rim ; Lee, Jeyull ; Choi, Jang-Young

Author_Institution

Univ. of Seoul, Seoul, South Korea

Volume

48

Issue

15

fYear

2012

Firstpage

913

Lastpage

914

Abstract

The offset-voltage compensation technique is proposed for an accurate current-source circuit. This current source is made of a transistor, a resistor, and operational amplifier feedback in order to achieve a high output resistance as well as high accuracy of a generated current signal. Discrepancy from the ideal value mainly results from the offset voltage of the operational amplifier. The transconductance amplifier is utilised with a feedback loop that is controlled by the switched-capacitor integrator. The proposed technique is incorporated in the light-emitting diode driver circuit applications and successfully verified with hardware measurement.

Keywords

constant current sources; driver circuits; feedback amplifiers; light emitting diodes; operational amplifiers; resistors; switched capacitor networks; transistors; current signal generation; current-source circuit; feedback loop; hardware measurement; light-emitting diode driver circuit application; offset-voltage compensation technique; operational amplifier feedback; output resistance; resistor; switched-capacitor integrator; transconductance amplifier; transistor;

fLanguage

English

Journal_Title

Electronics Letters

Publisher

iet

ISSN

0013-5194

Type

jour

DOI

10.1049/el.2012.0739

Filename

6248332