A Design Of The High Voltage Driver Of The White Light LED

With the development of technology, the lighting demand is increasing from our daily life tothe important national activities. As for LED, high efficiency, good quality of light, pure light color,high reliability and environmental protection, its advantages have attracted lots of people, moreand more families and large activities use LED lamps, now it is indispensable in our life.Generally, in the use of LED lamps, their driven voltages are very small, so, they are only forsimple decorations; they appear little in the high voltage applications. As we all known, thebrightness of LED is related to the current flowing through themselves. In order to improve theefficiency of LED, we try to control LED current to be constant to meet the usual requirements.With the rapid development of semiconductor material technology, high voltage graduallycame into the vision of researchers in the BCD, it has been favored by the developers. Simply tothink the high voltage BCD technology, it is a chip containing bipolar, CMOS and DMOS devices forhigh voltage technology. With the help of this technology, it allows us to solve the design of highvoltage integrated circuit, and avoid the over voltage loss of common devices.This article is based on a BCD technology, it realizes the white light LED driver under highvoltage, through the simple bridge rectifier circuit,it realizes AC-DC conversion, and simplifiedchip peripheral driving circuit design, on the other hand, it reduces the requirements of the chipworking environment. Pre-regulator, band-gap voltage reference modules, PWM and LDO VoltageRegulator modules are included in the design. Typical input voltage range of the chip is between85V to400V, output current level is mA to A. By adopting PWM signal, the chip efficiency improvesmuch.