谐振振铃的原因和危害及解决方法

The reason,risk and solution for resonant ringing

开关电源及D类功放中,因寄生电容和寄生电感的存在,导致电路产生谐振振铃,而振铃有着频率高、幅度大的特点,是导致EMC的关键因素,也是导致电路工作不正常的关键点之一。为解决这个问题,本文分析了振铃的产生原理,并用仿真电路验证,最后采用了缓冲电路(Snubber)的方法来消除谐振振铃,通过计算及实验,Snubber电路可以有效的抑制谐振振铃的产生,从而达到了消除谐振振铃的目的。

Because of the parasitic capacitance and inductance,there could be a resonant ringing in switching power and Class D amplifier circuit.the resonant ringing has the characteristics of high frequency and wide range,should be the key factor of EMC and one of the main points of circuit abnormal work as well.In order to solve this issue,this paper try to analysis the root cause of ringing with simulation circuit verifying,and find the way of Snubber Circuit to eliminate the resonant ringing,and it works by experiment data validation.