用于开关电源的EMI滤波器设计

EMI Filter Design for Switched Mode Power Supplies

给出了用转移矩阵[A]参数法分析电源EMI滤波器插入损耗的具体方法,介绍了电源EMI滤波器的几种基本结构。通过分析LISN网络和EMI噪声的特性,分别对共差模等效电路进行分析与设计。结合所要通过的EMC标准计算所需的插入损耗,选择合适的元器件构造电源EMI滤波器,最后通过试验验证了设计方法的正确性。

This paper presents a specific method that uses the transfer matrix [A] to analyze insertion loss of EMI filter, and then several basic structures of EMI filter are introduced. With analysis of LISN network and the characteristics of EMI noise, the equivalent circuits of common mode and differential mode are designed separately. Based on the EMC standard emission limit, the needed insertion loss is calculated. Then proper components for the EMI filter are chosen and a prototype EMI filter is built. At last the method of EMI filter design is verified by the experiment.