基于LT3496的可调光大功率LED照明电路  

High power LED driver with PWM dimming based on LT3496

作　　者：宋亮[1] 王晓东[1] 刘雯[1] 徐锐[1] 杨富华[1] 

机构地区：[1]中国科学院半导体研究所,北京100083

出　　处：《电源技术》2014年第1期97-99,共3页Chinese Journal of Power Sources

摘　　要：目前大多数多通道LED恒流驱动芯片的输出电流集中在100 mA以内,当每个通道需要输出高于100 mA的大电流时,通常要外加三极管以增大带负载能力,而凌力尔特公司生产的LT3496三通道LED驱动器的输出电流可高达750 mA,能够满足一般的大功率LED照明应用而不需要外加三极管。主要介绍了如何利用LT3496驱动芯片来设计多个大功率LED串并联的恒流驱动电路,并介绍了升压拓朴结构的基本原理及如何设计其中的元器件的参数。另外,采用了NE555定时器组成占空比可调的PWM脉冲发生器以实现对LED的调光。The output current of most multi-channel LED driver is less than 100 mA, so an external transistor must be used when the output of each channel is higher than 100 mA. LT3496, a three-channel LED driver, produced by Linear Technology Corporation, has the output current up to 750 mA. It can meet high power LED lighting applications without the external transistor. How to use the LT3496 to drive multiple high power LED strings in parallel with constant current control was mainly introduced, and basic principles of the boost topology and how to choose the components were also described. Furthermore, LED dimming was realized by using NE555 to design a variable duty cycle of PWM generator.

关 键 词：LT3496 LED驱动 PWM调光 

分 类 号：TM923[电气工程—电力电子与电力传动]