基于LLC多路LED均流驱动电路的研究

摘要

提出了一种基于LLC谐振的多路输出LED均流驱动电路,方案中DC/DC部分采用了LLC谐振,提高了转换的频率,同时能够实现原边开关管的零电压开通和副边整流二极管的零电流关断,减少了损耗,提高了系统的效率.LED的驱动部分采用了平衡电容隔离均流,输出达到很好的均流效果.PSIM仿真和样机测试均证明了该电路的可行性.%It proposes a circuit about multi-output constant current LED drivers,based on LLC resonant.The LLC resonant was adopted in the DC/DC circuit,improving the frequency of conversion.The switches on the primary side could work in zero-voltage-switching mode (ZVS),and the diodes on the secondary side could work in zero-current-switching(ZCS) mode,which decreased the loss of switching and improved the efficiency of the system.The balance capacitor was used in the LED driver circuit,and it was easy to achieve the balance of the current.Meanwhile,a prototype was proposed to test in the laboratory.It focused on the mechanism of the resonant and the balance of the current.The system has been simulated and verified,based on PSIM.