摘要：经典控制方案PWM是一种非常有效的技术，但在LED调光器中存在输出纹波问题。本课题采用华润矽威PT4207芯片，设计一种无人眼识别频闪、无相机识别频闪，输出电流精度5%，效率高，负载能力强，可调光范围10%-100%，控制能力强（理论满足50个驱动器复用控制信号）的恒流源LED驱动方案。其中使用PWM-模拟-PFM调光方案，改变开关器件关断时产生的发光断点，减少纹波，提高光照质量，同时使用光耦设计电路，实现驱动电流反比工作状态，提高驱动能力，达到一信号多控制的目标，并采用多级电流输出档位方案，满足了250mA-1000mA的电流输出范围。38147
同时为保证驱动器满足基本的稳定、耐温、复用信号能力强，进行了大量不同环境下的测试，得到了该设计方案的调光曲线、温度曲线、效率曲线等特性曲线，以及工程使用现场状态分析结论。最终得到了完整的高品质室内LED驱动器的设计方案和运行参数。
毕业论文关键词：绿色照明；无频闪；恒流源；调光范围；高品质。
 The Research of High Quality Indoor LED Driver
Abstract：The classical control method PWM is a very effective scheme, but there are many ripple problems in LED dimming. In the project, a constant current source of LED driver scheme designed by PT4207 chip made in Hua Run Xi Wei, with no light flash recognized by human eyes and frequently-used cameras, current output accuracy with 5%, high efficiency, good load capacity, adjustable light range between 10%-100%, powerful control ability（50 driver controlled by a common control signal in theory）. The PWM- analog-PFM dimming scheme used in the design in order to change light breakpoints produced by switch of switching component and decrease ripple, enhance light quality. Photoelectric couplers also used in the circuit, realizing the inversely proportional current condition of driver, enhancing driver ability, and achieving the objective that multi objects controlled by one signal. Current output range between 250mA-1000mA realized by Current output of scheme multistage.
    Meanwhile, many different environmental experiments were conducted in order to meet the performance including fundamental stability, thermal endurance, powerful multiplexed signals ability, acquiring dimming curve, temperature curve, efficiency curve of the design scheme and the conclusion of using in engineering construction site. Finally, the completed design scheme and operating parameter of high quality indoor LED driver have been obtained.
Keywords: green lighting; no light flash; constant current source; dimming range; high quality.
目录
1    绪论    1
1.1    照明发展史    1
1.2    课题目的与意义    1
1.3    国内外研究现状与水平    2
1.3.1    国外水平    2
1.3.2    国内水平    3
1.4    现有专利情况    4
1.5    主要工作    5
2    LED调光理论    6
2.1    可控硅调光    6
2.2    模拟调光    6
2.3    PWM调光    7
2.4    PFM调光    8
3    驱动方式    9
3.1    LED特性    9
3.2    恒流源与恒压源    10
3.3    指标要求    11
4    恒流源设计    12
4.1    芯片选型    12
4.1.1    PT4207简介    12 高品质室内LED灯驱动的研究:http://www.youerw.com/tongxin/lunwen_37083.html