How should the AC/DC interface filter of the power DTU be coordinated?

The DTU AC/DC interface filtering needs to be designed according to the voltage type and noise spectrum. An EMI filter is used on the AC side, including a common-mode inductor CML4532A-510T and X/Y safety capacitors. A π-type filter is deployed on the DC side, using a power inductor and electrolytic capacitors. An isolated DC-DC module is used in the AC/DC conversion section to suppress conducted noise. A key point in the design is impedance matching: the AC filter presents low impedance on the DC side, and the DC filter presents high impedance on the AC side. Parameters are optimized through system simulation, and measured conducted emissions meet EN55032 Class B standards in the 150kHz-30MHz range. This design ensures EMC compatibility of the AC/DC system.