Title :
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
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;
Journal_Title :
Electronics Letters
DOI :
10.1049/el.2012.0739
