20W小功率开关源的设计 毕业设计.doc

20W小功率开关电源的设计 2012年5月  20W小功率开关电源的设计 The Design of 20W Low-power Switching Power Supply 摘 要 开关电源具有功耗小，效率高，稳压范围广，体积小等突出优点， 在通信设备数控装置，仪表仪器影音设备，家用电器等电子电路中得到广泛应用。 TOP系列电源为美国POWER INTEGRATION公司生产的集成开关电源，具有集成度高，性价比高，外围电路简单，性能指标佳以及能构成高效率无工频变压器的隔离式开关电源等优点。目前已成为国际上开发中、小功率开关电源，精密开关电源及电源模板的优选集成电路。 本论文主要有以下内容： (1) 介绍开关电源的发展史、分类及发展趋势，开关电源常用的几种控制方法。为研究的论题—基于反激式变换器的开关电源研究作铺垫。最后讲述了本课题的研究意义和工作内容。 (2) 介绍反激式开关电源的工作原理以及 TOP223Y 芯片。 (3) 设计了基于TOP223Y芯片的单端反激式开关电源。根据 TOP223Y 的特性给出了单端反激式开关电源的工程设计方法。对外围电路的设计进行了分析和讨论。 (4) 对给出的具体实例电路进行仿真测试研究，得出结论并加以分析。 关键词:开关电源 TOP223Y 脉宽调制 单端反激式 Abstract Switching power supply with low consumption, high efficiency, wide voltage, small advantage in communication equipment, CNC equipment, instrument audio equipment, household appliances, etc widely applied in electronic circuits. TOP U.S. power supply for series of integrated production company need to switch power, has high integration, cost-effective, outer circuit is simple, performance and can form no better efficiency of the isolated transformer switch power supply, etc. At present has become the international development of small power switch power supply, switching power supply, selection of template and integrated circuits. This paper has the following content: (1) Describes the development history, classification and development trend of switching power supply, switching power supply commonly used control methods. For the study of topic-based on the research of switching power supply for flyback converter bedding. Finally describes the significance of the subject and content of work. (2) Introduced the working principle and TOP223Y of Flyback switching power supply chips. (3) Design based on single-end Flyback switching power supply for TOP223Y chip. According to the characteristics of TOP223Y gives single-end Flyback switching power supply design. Analysis and discussion on periphery circuit design. (4