LED Backlight Driver Implemented by Single-stage Linear Regulation Control (LRC) Technique for High Efficiency and Low Cost

摘要

LCD panel with the LED backlight can be controlled by the proposed linear regulation control (LRC) technique for high efficiency and low cost. The LRC technique removes most of the external passive components, which include inductor, E-cap, freewheel diode, and blocking diode. Due to single-stage operation without two-stage power consumption, small volume and high efficiency can be simultaneously ensured. Furthermore, the PLL function can guarantee the line voltage and current to be in phase so as to realize the high power factor (PF) for green power. High efficiency of 85% at 110Vrms and 87% at 220Vrms, high PF of 0.98 at 110Vrms and 0.96 at 220Vrms, and low THD of 18% at 110Vrms and 19% at 220Vrms are achieved.