Research Of Self-adaptive White LED Backlight Driver IC

White LED backlight driver IC is an important element of consumer electronics backlighting system. as a bridge between portable batteries and LED backlight unit, White LED backlight driver IC is widely used in mobile phones, MP4, laptops, LED TV, and other consumption electronic products. However, as the reduction of size of consumer electronics and a portable battery, white LED backlight driver IC based on traditional three-mode charge pump can not longer meet the requirements of the future consumer electronics.Intention of resolving the efficiency problem of White LED backlight driver IC, a new four-mode 1x/1.25x/1.5x/2x charge pump and his control circuit are proposed, and are embedded in white LED backlighting driver chip. The main contents of this paper include: 1, advance a new four-mode 1x/1.25x/1.5x/2x charge pump, which can provides 1 times,1.25 times,1.5 times and 2 times step-up features.2, design a new type of 1x/1.25x/1.5x/2x four-mode charge pump control circuit, which can automatically adjust the operation mode of charge pump.3, design of EN control, over-temperature protection and soft-start circuits.Finally, By using the Synopsys Hspice simulation software with 0.5μm BiCMOS model, the simulation results show that the designed self-adaptive charge pump white LED backlight driver IC efficiency can reach 92%, output current error is within 1.5%, average output voltages error is within 2.1%, with low power ripple, and no RF interference. Simulation results can meet the development requirements of chip performance.