LED Driver Chip Designed To Suppress The Current Ripple

LED lighting is a new light source, has a wide range of applications. It has incandescent, fluorescent incomparable advantages. Much higher than the efficiency of traditional lighting, safety and environmental protection no pollution, and it has extraordinary life. As in all aspects of our lives LED use, LED penetration rate have improved significantly. Unlike conventional light sources, LED requires a separate driver chip, because LED diode voltage belong to very sensitive, a tiny current transformation will bring great changes, and brightness of the LED is dependent on the size of an electric current. This makes the LED drive becomes more complex and requires constant current control driver chips. However, currently available LED drivers are more or less certain current ripple(ripple mainly from the mains 50Hz), which for the life of the LED, and the light effect has a significant impact. Therefore, LED flash frequency problems, both LED drive current ripple, for our social life has far-reaching impact of the current study is the problem for the LED lighting industry's top priority.To address this problem, we designed a LED drive current ripple rejection circuit can automatically adapt to the size of the drive current within a specific range. First, according to the LED driver circuit principle analysis of the current ripple suppression needs, and add adaptive ripple current capability. Then, all the modules are designed chip needs, including bandgap reference module, a linear regulator module, the operational amplifier module, the error amplifier module, a module overtemperature protection, undervoltage lockout module. And the simulation results are in line with the design requirements. Finally, all the modules to build together, using ASMC 0.5 BCD process design using Cadence ADE simulation software circuit simulation in the drive current range 100 m A to 1A, the use of LED STTH1L06 simulation, simulation results show that at 100 m A to 1A. under current conditions the drive current ripple suppressing effect is obvious, the amplitude of the input only 1% to 3%, and adaptive drive current of 100 m A to 1A.