重庆大学本科学生毕业设计（论文）LED 驱动电源设计专 业：电气工程与自动化重庆大学电气工程学院二 O 一一年六月Graduation Design(Thesis) of Chongqing UniversityDesign of Driver Power for LEDUndergraduate: Zhou HaoSupervisor: Prof. Tang ZhideMajor: Electric Engineering & AutomationSchool of Electric EngineeringChongqing UniversityJune 2011重庆大学本科学生毕业设计（论文） 中文摘要I摘 要该文针对 LED 驱动电源的设计需要，先简述了 LED 及其驱动电源的基本情况，包括 BUCK 电路及其控制电路的工作原理、稳定性分析等。然后以 UC3843电流控制芯片和 BUCK 电路为基础，设计出了一款车用 LED 驱动电源，并通过仿真实验，对电路进行了检验。文中详细介绍了 UC4843 的使用方法、该驱动电源的设计步骤以及具体参数计算。这款驱动电路工作在 12V 直流电压下，以 BUCK 电路为主电路，采用峰值电流控制模式，按照 PWM 调制方法，对两颗串联的 LED 进行供电，实现了恒流输出、欠压保护、过载保护、空载保护、斜坡补偿等功能，并且在仿真实验中均体现出了各部分的作用。这款 LED 驱动电源工作稳定，抗干扰能力强，输入范围广，输出电流平稳；通过简单改变供电方式，此电路还能用于不同领域。另外该文还对仿真实验结果进行了较为详细的分析，对补偿斜坡尾部上翘、电流采样电阻的至畸作用进行了讨论。关键词：驱动电源，峰值电流控制，PWM， LED，UC3843重庆大学本科学生毕业设计（论文） ABSTRACTIIABSTRACTThis article for the purpose of the design needs of LED driver power, firstly summarizing briefly the basic information of LED and its driver power, including BUCK circuit as well as its working principles of control circuit, the stability analysis etc. Then based on the UC3843 electric current control-chip and BUCK circuit, a vehicle LED driver power has been designed, and its electric circuit has been tested through the simulation experiments. This article describes the usages of the UC4843, the design process of the driver circuit and the specific parameter calculation in detail. This driver power works at 12V DC voltage, with BUCK circuit as the main circuit, adopting the control mode of peak current, in accordance with the PWM modulation method, providing power to two series connections of LED, bringing about the functions of under-voltage protection, overload protection, idle-load protection, slope compensation, and reflecting their respective functions in the simulation experiments. This LED driver power works stably, with strong anti-interference ability, wide input range; stable output current; by changing the way of power supply, the circuit can also be used in different fields. In addition, this article also carried on a more detailed analysis of the simulation experiment results, and carried out the discussion of abnormal functions about the upturned slope compensation and disruption of the current sampling.Key words：Driver power，Peak current mode control，PWM，LED，UC3843重庆大学本科学生毕业设计（论文） 目录目 录中文摘要 .ABSTRACT .1 绪论 .11.1 电光源 .11.2 大功率 LED 简介 .21.2.1 大功率 LED 发光原理 .21.2.2 大功率 LED 的特性 .31.3 LED 驱动电源研究现状 .61.3.1 LED 驱动电源的分类 .61.3.2 LED 及其驱动电源的市场 .72 降压性开关电源 .92.1 开关电源的特性 .92.2 BUCK 电路原理分析 .102.2.1 BUCK 电路基本原理 .102.2.2 BUCK 连续导通模式 .113 控制电路 .173.1 开关电源的调制方式 .173.2 开关电源的控制模式 .193.3 峰值电流控制模式的稳定性分析 .223.3.1 不稳定性的产生 .223.3.2 斜坡补偿技术 .244 UC3843 高性能电流模式控制器 .264.1 UC3843 的主要特性 .264.2 UC3843 的工作原理 .274.3 UC3843 的引脚及其功能 .284.4 UC3843 的内部结构 .294.5 UC3843 的各模块具体特性 .325 基于 UC3843 的 LE