Does the edge box network port transformer need to have EMC isolation function?

The common-mode choke and center-tapped capacitor built into the transformer of the edge computing box's network port are core components that meet EMC isolation requirements. The isolated transformer can block ground loops, isolating and discharging common-mode noise. Testing shows that transformers with a center tap grounded via a capacitor offer more than twice the EFT immunity of the untapped version. For RJ45 network port design, a transformer with the tap connected to signal ground via a 1kV 1000pF capacitor should be selected, along with a common-mode inductor CMZ2012A-900T (CM common-mode Z impedance 2012, size 2.0×1.2mm, 900T impedance 90Ω, 100MHz). This inductor should be placed on the PHY side of the transformer. If the transformer already has a built-in common-mode inductor, external components can be omitted, but impedance matching must be verified. For edge computing box gigabit network ports, integrated isolation devices such as HX5008NL are recommended, and the pulse transformer should meet IEEE 802.3 requirements with a 1:1 turns ratio and 1500Vrms insulation withstand voltage, complying with IEC60950 safety standards.