基于PF7900的恒流式LED背光灯驱动电路的设计

Design of constant current LED backlight driving based on the PF7900

为了提高效率,降低能耗,同时又能简化电路,节省成本,提出了PF7900恒流式LED背光灯驱动方案。用PF7900芯片与少量外围元件构成DC/DC升压电路来驱动LED背光灯工作;用分立元件构成恒流电路来控制LED背光灯的亮度,就可实现对LED的恒流驱动。该电路在节能方面和稳定性方面都较传统的LED驱动电路有很大的改善。实验表明,这种驱动电路的输出电压非常稳定,带负载能力强,亮度调节方便,是一款极具应用前景的电路。

In order to improve the efficiency,reduce energy consumption,as well as simplify the circuit and save cost,it proposed the scheme of PF7900 constant current LED backlight driving. It drives the LED backlight with PF7900 chip and a small amount of peripheral components constitute DC/DC booster circuit. And it is to use discrete component constitutes a constant current circuit to control the brightness of LED backlight,It can be achieved on LED constant current driver. The circuit has a great improvement in the aspect of energy saving and stability compared with the traditional LED drive circuit..The experiments show that the output voltage of driving circuit is very stable,load capability is strong and the brightness adjustment is convenient,It is a highly promising circuit.