Adjustable Original Edge Sampling Flyback Type Led Light Control Chip Design

With the increasing depletion of energy, people are more and more concerned about green energy. Development of productivity makes LED lighting unreachable cutting-edge technology any more. LED lighting becomes the favorite for the general public and also applies into daily life. Dimming LED lighting will have a tremendous market because of more environmental protected and live longer than common LED lighting.Currently dimming LED lighting market is in preliminary stage. In the overview, no matter what program, the basic requirment is accurate output, large dimming range, high power factor(PF), low total harmonic distortion(THD), small output ripple, good dimmer adaptability, small size and etc. Based on the above requirements, this paper invents a dimmable LED system with a power factor correction (PFC) as the first stage, Besides, we design a dimming flyback LED driver chip with primary control for small and medium power. The power factor correction makes the system power factor and total harmonic distortion performance well. Controller can precisely control the LED current upon primary side regulated(PSR). It spare optocoupler and secondary side regulated control circuit. It also minimizes the size.This article analyzes basic principle of light power-off and the characteristics of each model. It provides a complete set of dimmable LED lighting system. According to this system, it designs a primary side regulated dimming flyback LED driver chip. We design and stimulate the circuit with the analysis of the works to ensure high output current accuracy, a large current range dimming, quick start and perfect protection functions. Chips have been tapeouted by 1.5umBCD technology of new semiconductor manufacturing limited. Now it’s in the production. With future testing and customer feedback, it implements the expected functions.