High Power Factor LED Driver Chip Design With Dimming Function

With the rapid development of modern society, Green, energy saving, environmental protection has become an important part of China’s economic development. LED lights as a new type of green lighting, will gradually replace the development of the fluorescent lamp. It was loved by the people because of its highly efficient, energy-saving, environmental protection, long life and other advantages. With the development of LED lights, LED lights with dimming function are becoming the development of the object of the LED driver circuit. Such as the application in the phone’s LED display dimming, used in dimming of LED TV, in home lighting LED lights dimming, etc. The cost with dimming LED driver circuit due to the current high volume, complex structure, the dimming power factor is too low, low efficiency, and so on. These factors gradually limit the development of LED lights. Low-cost, dimmable, small volume structure, high power factor, low complexity is a now a hot research in the field of LED lights.The research projects focused on the current dimming LED driver circuit, which dimed with low power factor, circuit complexity, designed a dimmable, high power factor and the external circuit simple LED driver circuit. The drive circuit is applied directly to home lighting, can drive6-8W LED lights with4stalls LED lights brightness adjustment. Through the experiment verify the feasibility of the research, with dimming the PF value of not less than80%, efficiency up to90%or more.The main content of this topic research includes the following several aspects:1. This paper studies the significance of the current market prospects with dimming LED driver circuit and LED driver chip with high power factor and power conversion efficiency.2. With Fly-back architecture and switch mode dimming, the driver circuit not only makes the the LED dimming driving circuit becomes simple, and further improves the power factor of the circuit, and power conversion efficiency. 3. Chip circuit module design includes:the LDO module, bandgap reference, oscillator, counter, digital-to-analog conversion, and other circuits.4. Layout design including current mirrors matching, resistors matching, high pressure module with low voltage module placement, as well as the post-simulation and parameter extraction, after imitation verify.5. Build a board-level circuits, verified and tested results meet the expected design target.