Multi-channel constant current (MC3) LED driver

High-brightness light emitting diodes (LEDs) are promising for various lighting applications, such as the backlighting of liquid crystal display (LCD) panels and the street lighting. Many backlighting and street lighting applications require the multi-channel constant current (MC3) driver to achieve better performance and higher reliability. The purpose of this paper is to introduce a simple and effective MC3 LED driver and explain its control concept and mechanisms. Coupled inductor concept is employed in the driver's circuit to improve the output current cross regulation. This paper also provides a general model to describe the current cross regulation (CCR) among multi-channel outputs mathematically. By using this model, factors that affect cross regulation can be easily located and analyzed. Simulation results are provided to verify the concept.

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