发布时间：2015-03-15 来源：人大经济论坛

应用物理学专业论文范文 目录 中文摘要i 英文摘要ii 目录iii 一、绪论1 1.1 白光LED特性1 1.2 开关电源原理结构2 1.2.1 开关电源基本原理2 1.2.2 开关电源组成2 1.3 开关电源分类2 1.3.1按驱动方式分类2 1.3.2 按电路结构方式分类3 1.3.3按控制原理分类3 1.4 LED驱动芯片的发展4 二、电路设计原理6 2.1 恒流控制芯片介绍6 2.2 典型电路应用及改进6 2.3 电路分析7 三、硬件电路制作9 3.1 驱动电路制作9 3.2 白光LED光源制作9 四、应用测试与性能分析10 4.1 电源效率测试10 4.2 输出恒流测试10 4.3 光源表面温度测试11 4.4 光效测试11 五、总结与展望13 5.1 总结13 5.2 展望13 致谢14 参考文献：15 摘 要 近几年，大功率白光LED（Light Emitting Diode）技术得到了很大的发展。LED作为一种固体光源，具有节能、环保、结构牢固、寿命长、启动时间短、体积小、低压驱动等优点，应用前景十分巨大。 使用LED照明系统需要一个AC/DC转换器。在过去，一般使用分立器件搭建AC/DC转换器作为电源，使用市电交流电给电源供电。由于在AC/DC电路和电流控制电路的损耗，这种LED照明系统相比于传统白炽灯和荧光灯并没有优势。随着半导体制造技术发展和高压BCD工艺成熟，出现了能耐500V的高压金属氧化物半导体场效应管(MOSFET)，使得设计制造高压集成电路成为了可能。 本文我们采用一款支持交流85V-265V输入的恒流控制芯片，设计了一种体积小、效率高、性能稳定、价格便宜的PWM (Pulse Width Modulation) 开关电源，用以恒流驱动大功率白光LED。实测电源效率高达90%。由于芯片内部已有过温保护、输出短路保护和输出开路保护的设计，所以此款设计的电路安全性高，非常适合应用于系统效率要求高、安全性要求高的实际照明中。 关键词：白光LED、开关电源、恒流驱动 Abstract In recent years, high-power white LED (Light Emitting Diode) technology has been greatly developed. LED is a kind of solid light source. It has an enormous application prospect because of its advantages , such as energy conservation, environmental protection, firm structure, long life, short start-up time, small volume, low operating voltage. The LED lighting system needs an AC/DC converter. In the past, the general use of AC / DC converter was made by separate devices as a power source, and using mains alternating current to power supply. As the loss of AC / DC circuit and current control circuit, resulting that it has no advantage of LED lighting compared to traditional incandescents and fluorescent lamps. As semiconductor manufacturing technology development and high-voltage BCD process maturity, there 500V high-voltage capability of metal oxide semiconductor field effect transistor(MOSFET), making design and manufacture of high-voltage integrated circuits as possible. In this paper, we adopt a 85V-265V AC input to support the constant current control chip, and design a small size, high efficiency, stable, inexpensive PWM (Pulse Width Modulation) switching power supply for high-power white LED constant current driver .The measured power efficiency up to 90%. As the chip has been over-temperature protection, output short circuit protection and output open-circuit protection design, so this design of the circuit is very safe and suitable for systems that require high efficiency, high safety requirements in the actual lighting. Keywords: White LED , switching power supply , constant current drive