How to select the filter for the communication port of a power DTU?

The selection of DTU communication port filters needs to be based on the interface type, signal rate, and noise spectrum. For RS485, a common-mode inductor CML3225A-510T and a TVS diode SMBJ6.5CA are selected. For Ethernet, an RJ45 connector with integrated filtering is used. For high-speed serial ports, a low-capacitance π-type filter is used, with a PBZ1608A-102Z0T ferrite bead and a 100pF capacitor. When selecting filters, the cutoff frequency should be higher than the signal frequency without affecting signal integrity. The selection effect is verified through eye diagram testing. Correct selection will ensure the port passes EMC testing and guarantees communication quality.