基于积木式交错并联的平面全集成EMI滤波器

为了减少电磁干扰(EMI)滤波器的体积,提高开关电源的功率密度,提出一种基于积木式交错并联的平面全集成EMI滤波器。根据差、共模噪声的频段分布规律,采用温度稳定性较高的薄膜介质材料进行交错并联来实现共模电容的集成,采用电气性能较稳定的Ⅱ类陶瓷材料X7R来实现差模电容的集成,采用PCB绕组来实现共模电感和差模电感的集成,给出了平面全集成EMI滤波器高频差、共模等效电路及其插入损耗的计算公式。仿真和实验验证了所提出的平面全集成EMI滤波器的有效性及其高频差、共模等效电路和插入损耗公式的正确性。

Planar Completely Integrated EMI Filter Based on Stacked-Type Interleaved Connection

In order to reduce the size of filter and improve the power density of switch and power supplies,a passive integrated EMI filter structure based on planar stacked-type interleaved parallel connection is proposed in the paper.According to frequency range distributed rule of differential mode noise and common mode noise,film medium materials with higher stability of temperature is interleaved to realize the integration of common mode capacitance.In order to realize the integration of differential-mode capacitance,the Ⅱkind ceramic material X7R with higher stability of electric property is used.The PCB winding is used to realize the integration of common-mode inductor and differential mode the inductance.The equivalent circuits of common-mode and differential-mode in high-frequency modeling of this EMI filter are given,furthermore,the calculated formulas of insertion loss are deduced.The results of simulation and experiment verify the effectiveness of planar completely integrated EMI filter,and the correctness of the equivalent circuits of high frequency differential-mode,common-mode and the formulas of insertion loss.