Title :
Efficient LED back-light power supply for liquid-crystal-display
Author :
Choi, W.-Y. ; Kwon, J.-M. ; Kwon, B.-H.
Author_Institution :
Dept. of Electron. & Electr. Eng., Pohang Univ. of Sci. & Technol., Kyungbuk
fDate :
3/1/2007 12:00:00 AM
Abstract :
A highly efficient light-emitting-diode back-light power supply is proposed for liquid-crystal display. The proposed power supply consists of a bridgeless boost rectifier for power-factor correction and the asymmetrical half-bridge flyback converter with synchronous rectifier (SR) for DC-DC power conversion. In the proposed bridgeless boost rectifier, the diode reverse-recovery losses are reduced by achieving zero-current turn-off of the output diodes, as well as zero-current turn-on of the additional diodes. The reverse-recovery transients of the diodes are improved by a simple passive snubber circuit. For a DC-DC converter, the asymmetrical half-bridge flyback converter operates under zero-voltage switching for the power switches, and the SR switch operates under zero-current switching. The analysis of the proposed converter is presented and its design considerations are discussed in detail. Experimental results based on 28 V, 300 W back-light power are provided to demonstrate the performance of the proposed converter
Keywords :
DC-DC power convertors; LED lamps; liquid crystal displays; power factor correction; power supply circuits; rectifiers; snubbers; zero voltage switching; DC-DC power conversion; LED back-light; diode losses; half-bridge flyback converter; light-emitting-diodes; liquid-crystal-display; power supply; power switches; power-factor correction; reverse-recovery transients; snubber circuit; synchronous rectifier;
Journal_Title :
Electric Power Applications, IET
DOI :
10.1049/iet-epa:20060222
