《LED驱动电路的研究与设计》-毕业论文.doc

摘 要 在能源和环境问题日趋严重的今天，以高效、节能、环保以及长寿命为主要特点的LED获得了人们的重视，同时随着经济的发展，LED(发光二极管)应用随需求而变得急剧增大，它已经广泛地应用于电信.、邮政、金融、交通等各个行业。随着其性能的提高以及生产成本的下降，LED将逐步取代白炽灯和荧光灯，引起人类照明史上又一次革命。而LED的应用离不开它所需要的驱动控制电路，通过驱动电路来获得良好而平稳的电流，使LED显示更加均匀、漂亮，来满足各种场合的应用要求。 本文从LED的发展现状出发，选择合适的LED驱动电路，介绍了LED照明的特点以及基本的光学特性，同时给出LED驱动电源的特殊性以及供电的基本要求，为此需要利用降压型或者升压型开关变换器进行调压，最后将误差信号反馈，之后成为脉冲宽度调节的输入信号来控制开关的开断，从而构成整个LED驱动电路，为LED负载提供稳定的电流，达到目的。 最后通过Saber软件来仿真基于Buck变换器的LED驱动电路，在20ms的仿真周期内，获得平稳的电流，并且将误差控制在0.5%以内，完成预期的要求。 关键词：LED；驱动电路；Saber软件；Buck型开关变换器 ABSTRACT Nowadays the Problems of energy sources and environment become more and more serious ,semiconductor lighting has won people’s attention for its unique attributes of low energy consumption，low pollution，long life and high efficiency. As the same time, the development of economy needs for applications of LED increase dramatically and it is used widely in telecom，mail，finance，traffic. As the quality of power LED improves and the cost of power LED reduce, semiconductor lighting will replace incandescent and fluorescent lighting gradually. Drive-control voltage is necessary for application of LED，because driven circuit provides good and steady current to make display of LED suitable for many applications. In this paper, the current situation of the development of LED，Select the appropriate LED drive circuit.Describes the characteristics of LED lighting, and basic optical properties，At the same time，LED drive power is given the special nature and the basic requirements of power supply，This requires use of buck or boost switching converter for voltage regulator，Finally, after the feedback deviation signal as the input signal pulse width modulation to control the switch breaking，Which constitute the entire LED driver circuit, to provide a stable load for the LED ，and Achieve the purpose . Finally, use saber software to simulation based on buck converter LED drive circuit, in the 20ms of the simulation cycle to obtain a smooth current, And will be less than 0.5%