基于DPA425的防浪涌开关电源设计

基于DPA425的防浪涌开关电源设计(论文12000字)
摘要：为了提高能量利用率,本文提出了一款基于DPA425的大电流12V DC-DC转换器。开关电源通过对过欠电压保护、限流电路、变压器、输出整流、磁复位、输出滤波等部分进行优化设计，使得输出电压稳定为12V，同时具有大电流。通过对布局引线的优化，防浪涌限流电路，并且选取低EMI的钽电容，降低了总体电路的电磁干扰。输入电压：24V DC（变化范围18V～36V）。输出电压：12V DC。输出最大电流：1A。
关键词：DC/DC；开关电源；DPA425；防浪涌；电磁干扰

Design of Switching Mode Power Supply Based on DPA425 to Prevent Surge Current
Abstract：In order to improve the energy utilization, this paper presents a high current 12V DC-DC converter based on DPA425. Through the over-voltage protection,current limiting circuit, transformer, output rectifier, magnetic reset, output filter and other parts of the optimal design,switching power supply provides the output voltage stability of 12V,which has high current. Through the optimization of the layout lead, anti-surge current limiting circuit, and select the low EMI tantalum capacitor, the overall circuit of electromagnetic interference is reduced. Input voltage: 24V DC (variation range 18V ~ 36V). Output voltage: 12V DC. Output the maximum current: 1A.
Key words：DC / DC; switching power supply; DPA425;anti-surge;Electromagnetic interference
 

目录
1引言    3
1.1本课题的目的及研究意义    3
1.2防浪涌开关电源的研究现状和进展    3
2开关电源基本原理    5
2.1开关电源分类    5
2.2 开关电源的电路结构    6
2.3器件与芯片简介    6
3防浪涌开关电源硬件电路设计    9
3.1DPA425的设定    9
3.2 偏置电压的产生    9
3.3 箝位电路的设计    12
3.4 AP法设计变压器    13
3.5磁复位电路    14
3.6输出电路的设计    14
3.7 光耦合反馈电路的设计    15
3.8电磁兼容（EMC）    17
4 测试结果与分析    18
4.1电路原理图与PCB    18
4.2测试结果分析    19
5总结    20
参考文献    21
致谢    22