毕业论文-武瑞阳.docx

小功率开关稳压电源设计
摘要
随着电子设备的飞跃发展,电子系统的心脏——电源也得到了迅速的发展,并对其要求越来越高。开关电源被誉为高效节能电源,它具有稳压范围宽、功率密度比大、重量轻等优点,同时它在开关管上较少的能量损耗,使它与线性电源相比具有较高的效率,最高效率可达90%以上,从而使它在移动便携式设备中得到了广泛的应用,因此开展开关电源项目研究具有重要意义。
目前开关电源正向集成化、智能化的方向发展。高度集成、功能强大的单片开关电源代表着当今开关电源发展的主流方向。本论文围绕当前流行的单片开关电源芯片进行了小功率开关电源的研究,设计出一种实用的单路输出精密通用式开关稳压电源,可用作半导体激光器驱动电源中的精密电压源。
该设计由五个模块电路构成:输入整流滤波、功率转换电路、高频变换器、输出整流滤波和控制电路。该电源共使用3片集成线路:TOP249Y6端单片开关电源(IC1)、线性光耦合器PC817A(IC2)、可调式精密并联稳压器TL431(IC3)。本论文中对该电源的滤波、整流、反馈、启动及保护电路等分别作了细致的研究工作,并通过反复试验取得了高频变压器设计宝贵经验,掌握了单片开关电源设计的核心技术。
关键词:单片开关电源,脉宽调制,高频变压器,纹波
The Design of Low Power Switching Power Supply
Abstract
With the rapid development of electronic equipment, electronic system of the heart -the power has been rapid development and its increasingly high demand. Known as energy efficient switching power supply, it has wide voltage range, power density than large, light weight, etc., while it is switch it on less energy pared with the linear power supply with high efficiency, maximum efficiency of more than 90%, making it portable devices in mobile has been widely used to carry out switching power supply projects therefore important to study.
Toward the present switching power supply is integrated, intelligent direction; highly integrated, powerful single rose on the power of today's switching power supply represents the mainstream of development direction. This paper focus on the popular single-chip switching power supply chip for a small switching power supply of the study, design a practical single-output precision universal regulated switching power supply, laser diode driver can be used in the precision voltage source.
The design consists of five modules circuits: input rectifier filter, power conversion circuits, high frequency converters, output rectifier filter and control circuit. The power of integrated circuits using 3: TOP249Y6 end chip switching power supply (IC1); linear opt coupler PC817A (IC2); adjustable precision shunt regulator TL431 (IC3). The power supply fi