多路输出反激式开关电源设计模板.pdfVIP

精品文档 精品文档 多路输出反激式开关电源设计 摘 要:以UC3844 芯片为控制核心，设计并制作了多路输出反激式开关电源。完 成了多路输出反激式开关电源系统设计，完成具体模块电路详细设计，包括 EMI 滤波电路、前级保护和整流桥电路、缓冲吸收电路、高频变压器、UC3844 的启动 与驱动电路、电流检测和过流保护电路等。合理选择、设计和分配了开关电源各 电路参数；设计出电路原理图，根据设计规范制作出 PCB，并组装出电源样机， 最后对设计的样机进行测试验证。 开关电源样机输出电压稳定性较高，输出电压纹波较小，符合设计规范小于 80mV 的要求；样机整体测试结果表明，电源各项指标均符合要求，输出稳定，性 能较好。 关键词：开关电源；反激式；UC3844 ；模块化 Design of Multi-output Flyback Switching Power Supply Abstract: It was designed and produced a set of multiple output fly-back switching power supply, using the chip UC3844 as the control core. The design of the system and specific module circuits was completed. The module circuits include EMI filter circuit, level protection and bridge rectifier circuit, snubber circuit, high frequency transformer, start and drive circuit of UC3844, current sensing and over-current protection circuit. The parameters of switching power supply circuit were chose, designed and distributed reasonably. According to the schematic circuit design and design specifications, we produced the PCB, and assembled the prototype of power supply, also finished the test in the final. The higher stability of the output voltage of the switching power supply prototype, the output voltage ripple is small, meet the design specifications to the requirements of less than 80mV; The prototype of the overall test results show that the power of the indicators are in line with the requirements, output stability, better performance. Keywords: switch power supply；flyback ；UC3844 ；Modular 精品文档 精品文档 目 录 1 概 述1 1.1 课题研究背景与意义1 1.2 课题设计内容1 2 反激式开关电源系统分析1 2.1 反激变换器工作原理分析1 2.2 控制电路分析3 2.3 系统整体架构5 3 系统设计5 3.1 变压器设计5 3.2 控制芯片选择10 3.3