Design of a white LED backlight driver IC based on a new three-mode charge pump

摘要

Using CSMC 0.5µm process model, a white LED backlight driver ASIC with constant-current output based on charge pump was designed. A new three-mode charge pump and LED driver modules with high-precision driving current matching were used to improve performance of the chip. The samples of chip were tested in the temperature from −40°C to 85°C and the voltage from 2.5V to 5.5V. The result indicated that, the standard output current of the chip is 80mA, the maximum output current is 124mA, the shutdown current is 0.36µA, the error in output current between channels is 0.5%, the error in output current between chips is 0.8%, and the maximum conversion efficiency of the chip is 92%.