Study And Design Of LED Driver

With the shortage of global resources, the rising of people’s awareness about energy saving, energy saving LED lightings is more and more favored by the market. LED is a semiconductor light-emitting device, because of its structural features, it will not like the traditional light bulb to produce heat deposition and filament light easy to burn, the light fades and so on. One of the advantages of LED lights is its long life, typically ten times more than traditional incandescent. Beginning in October2012, the state will gradually plan to stop the importation and sale of ordinary incandescent lamps. Accelerate the pace of LED lighting popularity through state’s subsidies. Because the price of LED lights in current market is times or even ten times as the ordinary incandescent, it has not been widely accepted by the general public. However, with the continuous improvement of LED related technology, the cost of LED lighting is bound to be reduced, so that more people will accept. Although at this stage LED lighting products is not perfect, the development of LED lighting industry is also not perfect, but with the support of government policy, and a growing number of large enterprises and high-end talent to enter the industry, LED technology will be more mature, LED lighting will also be a universal trend. It now appears that a technical bottleneck of restrict the LED development is the LED driver, because the LED driver is considered as the LED lighting’s heart, LED driver’s quality directly affects the efficiency and life of the LED light. So the rapid development and popularization of LED industry requires the development of the low-cost, high-efficiency LED driver power supply.This paper based on the LED driver circuit’s design cost and efficiency considerations, designed a LED driver power supply of two-stage power topology. Paper analyzed the LED’s electrical characteristics and the driving method, and selected design plan, which include Boost power factor correction circuit topology and LCC resonant circuit topology, and select the NXP’s UBA2013as control chip. Secondly, it describes the need for power factor correction, and formulates the power factor correction topologies’work principle such as Buck circuit, Buck-Boost circuit and Boost circuit topology. Then studied Boost power topology’s work mode with the control chip, and designed the main component’s parameters such as output filter capacitor, Boost inductor, MOSFET, and output diode device. Through detailed analysis and research on the second stage topology LCC resonant converter circuit’s all kinds of operating modes, designed the parameters of the LCC resonant converter’s resonant inductor, resonant capacitor. Subsequently referred electromagnetic compatibility issues in the LED driver power supply’s design, analyzed the conducted interference which includes common mode and differential mode interference. By analyzing their work principle, designed the EMI filter and introduced some manners of Radiated interference suppression. Finally, based on the analysis of the previous study, designed a Boost+LCC two-stage topology LED driver power supply prototype. With the LED load, the LED driver tested, including test performance, the main waveform, EMI test results and so on. The test results show correctness of the theoretical analysis and feasibility and reliability of the design solution.