This article presents a control strategy based on simple digital pulse-width modulation （DPWM） and pulse-skip modulation （PSM） for a DC-DC boost converter, to drive a luminance-regulated white light emitting diodes （WLEDs）. The presented control strategy not only retains most of the advantages and flexibilities of traditional digital PWM, but also reduces complexity and cost. Based on analyzing the principle of the presented control strategy, the white light emitting diode （WLED） driver is designed and simulated using the 0.6 μm CMOS process. Simulation results of the boost converter show that the power efficiency is above 76% for a full load, with a peak efficiency of 88% when supply voltage varies from 2.7 V to 5.5 V. The control strategy overcomes low efficiency for PWM mode with light load.
LIU Xin GUO Shu-xu CHANG Yu-chun ZHU Shun-dong WANG Shuai
