Performance Improvement of a Boost LED Driver With High Voltage Gain for Edge-Lit LED Backlights

This brief proposes a new method for improving the performance of a dc/dc boost converter used as a light-emitting diode (LED) driver for edge-lit LED backlights. The proposed method uses a passive snubber circuit that consists of two capacitors, two diodes, and an inductor; it improves the power efficiency of the dc/dc boost converter at the high duty ratio of the main switch by providing zero-current switching turn on and charge pumping operations. To verify the effectiveness of the proposed method, a new boost LED driver with the proposed passive snubber was built and tested at the various output power levels dissipated by LED backlights. The power conversion efficiency of a boost LED driver with an input voltage of 24 V and an output voltage of 114 V was measured as 94.80%, 94.15%, and 92.82% for output power of 40, 70, and 100 W, respectively; these values are 6.08%, 4.47%, and 3.67% higher than conventional values.