单级PFC反激式LED电源的研究与设计

Study and Design of the Flyback LED Driver with Single-stage PFC

针对目前LED驱动电源功率因数不高和效率低等问题,设计了一款单级PFC反激式LED恒流驱动电源,其输出功率为40 W。电源采用临界导通模式的AP1661作为主控芯片,在单级结构上既实现了功率因数的校正,又实现了DC/DC级的降压、高低压的电气隔离,并为LED提供了恒定的电流,保证了LED稳定发光。分析了临界导通模式的单级PFC反激式的特殊电路结构特性,设计了恒流限压反馈回路,满足了LED恒流的特殊要求。实验测试结果表明,该电源功率因数高于0.92,效率在0.87以上,在满足功率因数要求的同时实现了高效率和低成本,符合LED驱动电源发展的趋势。

For the existing problems of LED driving power with low power factor and efficiency,a single-stage PFC flyback LED constant current driving power is proposed with,its normal power output40 W. The AP166 is adopted as main control chip for critical conduction mode in the single-stage structure of the power,with the power factor correction achieved and the step-down of DC / DC level and the electrical isolation of high and low voltage realized. It can provide constant current for LED and ensure LED brightness stability. Through analyzing the characteristics of critical conduction mode of special single-stage PFC flyback structure to realize the design of constant-current limitary-voltage feedback loop,the special requirements of LED constant current is satisfied. It is experimentally shown that the power factor is kept above 0. 92 with efficiency above 0. 87 and power factor requirements are met while high efficiency and low cost realized in line with the development of LED driving power.