准谐振反激式开关电源设计

摘要

设计了一种基于UCC28600控制器的准谐振反激式开关电源电路，分析了准谐振反激式开关电源的工作原理及实现方式，给出了电路及参数设计和选择过程，以及实际工作开关波形。实验证明，准谐振反激式开关电源具有输入电压范围宽、转换效率高、低EMI、工作稳定可靠的特点。准谐振技术降低了MOSFET的开关损耗，提高产品可靠性。此外，更软的开关改善了电源的EMI特性，允许设计人员减少滤波器的数目，降低了产品成本。%A kind of quasi-resonant flyback switch power supply circuit based on UCC28600 controller is designed in this paper. The working principle and the realization method of quasi-resonant flyback switch power supply are analyzed. The circuit, design and selection process of parameters and switching waveform are given. Experiments show that quasi-resonant flyback switching power supply has the characteristics of wide input voltage range,high conversion efficiency and low EMI,and works stable and reliable. The quasi-resonant technique reduced the switching loss of MOSFET,and improved product reliability. In ad-dition,the softer switch improved EMI characteristics of power supply,reduced the number of filters and the cost of products.