一种新型升降压LED驱动电源

A novel Boost-Buck LED driver

现阶段利用发光二极管(LED)作为快速光源十分普遍,随着LED功率不断提高,高亮度的LED灯具有取代传统照明灯具的趋势,应用潜力非常大。提出了一种新型升降压变换器作为高亮度白光LED灯的驱动方案。主电路由前级Boost和后级Buck组成,采用固定导通时间控制策略,实行前级限幅后级闭环控制,结构简单,无需补偿电路,动态响应速度快。建立了主电路的稳态与小信号模型,对控制环路进行了理论分析,运用PSIM软件进行了仿真验证。

Nowadays,light-emitting diode（LED） is applied as fast light source widely,the high light LED has a big potential of application and is trying to take the place of classic light source.A novel Boost-Buck converter as high brightness white LED lamp driver circuit was provided in this paper.The main circuit was composed of Boost part ahead and Buck part behind,using constant on-time（COT） control strategy,limiting the range of former part and controlling back-end with closed loop.It has simple structure,need no compensate circuit and has fast dynamic response.The static mode and small signal mode of the converter was made and the principle of control loop was analyzed and the system circuit with PSIM was simulated in this paper.