摘要：随着生活质量的提高，LED 作为一种绿色低碳照明越来越被人们所追求。和传 统照明比较，LED 的显著特点在于低耗高效，寿命长，显色效果极好。LED 电源驱动是 把输入电源转换为特定的电压电流来驱动 LED 发光的电压转换器。它的输入可以是高压 工频交流（即市电）、低压直流、高压直流、低压高频交流（如电子变压器的输出）等， 而 LED 驱动电源的输出大多数可随 LED 正向压降值的变化而改变。本文先介绍了 LED 的特性以及它的连接方式，LED 的驱动方式及其优缺点，然后着重讨论了反激式拓扑结 构，最后在设计电路参数的基础上，运用 Pspice 软件进行了仿真，通过仿真进一步验 证了电路设计的可行性。72644

毕业论文关键词:  LED 驱动电源，恒流驱动，反激式，峰值电流控制

Abstract：With the improvement of the quality of life, as a kind of green low carbon lighting, LED has been increasingly pursued by people。 And compared with traditional lighting, LED features are of high efficiency and low energy consumption, long service life and excellent color rendering。 LED power driver is a voltage converter which converts the input power into specific voltage and current to drive the LED。 Its input could be high voltage  power frequency AC (Utility power), low voltage DC, high voltage DC, low voltage high frequency AC (such as the output of electronic transformer) etc。, then most output of the LED driver power can change with the LED forward voltage drop value 。 Firstly, the paper introduced the characteristics of LED and its connection mode, LED driving mode and its advantages and disadvantages。 Then I seriously discussed the flyback topology structure。 Finally, on the basis of the design of circuit parameters, I used the PSPICE software to simulate, and the simulation results further verify the feasibility of the circuit design。

Keywords：LED drive power, constant current drive, flyback, peak current control

目 录

1 绪论 5

1。1 课题研究背景与意义 5

1。2 论文主要研究内容 6

2 LED 简介 6

2。1 LED 发光原理 6

2。2 LED 电学特性 7

2。3 LED 连接形式 8

2。3。1 整体串联形式 8

2。3。2 整体并联形式 8

2。3。3 混联形式 9

2。3。4 不同连接形式比较 10

2。4 LED 驱动方式 11

2。4。1 LED 恒压式驱动 11

2。4。2 LED 恒流式驱动 11

3 DCM 反激变换器基本原理 12

3。1 断续导通模式 Flyback 变换器 12

3。2 PWM 控制模式