Resonance-Based Optimized Buck LED Driver Using Unequal Turn Ratio Coupled Inductance

Abstract

Losses in light-emitting-diode (LED) driver cause increasing temperature and shorten their lifespan. Therefore, improving the efficiency of LED drivers not only saves energy but also is indispensable to increase their lifespan. In this article, a new LED driver topology is proposed to improve the performance of valley switching by decreasing the mosfet switching losses. The proposed topology is designed in a way that the mosfet works at the significantly lower switching and conduction losses in compared with conventional LED drivers. It elaborates how the proposed topology also improves the overall efficiency by decreasing power losses in other main elements of the driver, including inductance and diode. In addition, a new valley switching implementation is introduced for the new converter, which decreases the cost and dimension of the LED drivers. The experimental results confirm the high efficient operation of the proposed LED driver by reaching the efficiency up to 97% at a wide range of operating voltage.