一种LED背光灯镜像恒流电路

LED backlight mirrored constant current circuit

本设计电路适用于LED背光灯的恒流源,该电路包含镜像自调恒流电路、镜像恒流电路、Boost恒流驱动器、Boost升压电路、过压保护电路、Boost调整电路。其中镜像自调恒流电路包括驱动源晶体管、电流镜晶体管、比例电阻、取样电阻、LED灯。采用模拟调光方式镜像恒流原理驱动多路LED灯串,使多路LED灯发光强度稳定,噪声小,光谱连续;具有可方便扩展LED灯路串,以较低成本,简单设计就可解决LED背光灯恒流驱动通道端口过多、复杂的问题等优点。

The design circuit is suitable for the constant current source of the LED backlight, which comprises a mirror self regulating constant current circuit, a mirror constant current circuit, a Boost constant current driver, a Boost boost circuit, an overvoltage protection circuit, and a Boost adjusting circuit. The mirror self regulating constant current circuit comprises a driving source transistor, a current mirror transistor, a proportional resistance, a sampling resistor and a LED lamp. The analog dimming method is used to mirror the constant current principle to drive the multi-channel LED light string, which makes the light emitting intensity of the multi-channel LED lamp is stable, the noise is small, and the spectrum is continuous. It can be easily extended LED lamp string, with low cost, simple design can solve the LED backlight constant current drive channel port too much, complex problems and so on.