【摘要】 在设计和选用电源滤波器的过程中系统工程师发现,加了滤波器以后作用不大,甚至会发生某些频段的噪声变大。造成该现象的主要原因之一是电源滤波器的输出阻抗和开关电源输入阻抗之间相互匹配。分析了滤波器输出阻抗和开关电源输入阻抗匹配的原因,并给出了开关电源输入阻抗值的测量方法。更多还原

【Abstract】 During process of design and selection of power supply filter, system engineers find that sometime, the adding of power supply filter have no proper role, but even make more noise at some critical frequency section. One of the main reasons is that the input impedance of the switching power supply matches with the output impe - dance of the power supply filter. And the reason of above mentioned matching was analyzed, while the measuring method of the input impedance value of the switching power supply was given out.更多还原