A Multi-output 200W LED Lamps Driver

With the severe global energy shortage, the concept of green lighting is rapidly spreaded. Due to the advantages of high efficiency, long life, pollution-free and safety, white LED becomes popular in the filed of general illumination, making the design of reliable LED driver a hot issue in both academia and industry.In this paper, a multi-output LED lamps driver is designed according to the practical requirements for streetlight. The cascaded three-stage configuration is selected, based on the analysis of operational principles and the comparison with different counterparts. First of all, the Boost PFC module working in critical conduction mode (CRM) is introduced. The design equations are accomplished, giving the circuit parameters. Secondly, the principles of the half-bridge resonant converter are presented. Further more, the performance of LLC resonant converter is analyzed, using fundamental approximation method in detail, and the influence to the converter characteristics due to the parameter variations are discussed. The resonant tank components and the controller circuit are also covered. Finally, a comparison between two kinds of constant current control methods for LED is done, leading to the design of a constant current Buck converter.Adopting the proposed scheme, a 200W LED driver with multiple constant current outputs is designed. The prototype is built and tested, and experimental results verify the effectiveness and feasibility of the proposed approach.