An integration of buck converter topology for high-efficiency used in LED driver circuit

This paper presents an interleaved integrated buck converter for a high efficiency LED driver circuit. This integrated circuit can drive a high-power LED (1W - 3W). Assembled in matrices, it is able to drive multiple high-power LEDs. The operation principle, the power loss levels of buck converter, the design approach, technology of chip and the choice of passive components are analyzed and discused in detail. The prototype of an integrated buck converter is designed and tested for the input voltage 3.3V, current load from 0.3A to 1A at a switching frequency of 500kHz. Experimental results of four buck converters connected in parallel to drive eight 1W Lumileds show demonstrative and satisfactory results with the highest efficiency of 97.2% at the nominal load.