A high-efficient WLED driver using light-balanced-controlled techniques with current-locked loops

摘要

The proposed high-efficient WLED driver using light-balanced-controlled techniques with current-locked loops is presented in this paper. This LED driver has 500:1 current sensing ratio and 1 kHz PWM dimming frequency. The maximum output current of the buck converter is 100 mA and the output voltage range is from 3.5 to 4.8 V with a 20 and 18 μH off-chip capacitor and inductor, respectively. The maximum efficiency of the proposed LED driver is 87.8% and the current difference between each LED string is 1.33%. And it is fabricated with TSMC 0.35 μm 2P4 M CMOS processes. The chip area is 1.52 mm × 1.36 mm.