Transformer between Ethernet PHY and RJ45 connector will block line to ground surge?

[Elson Ong Cheng Ching]

I am not quite understand this sentence.

"Transformer can block line to ground surge discharge energy. If the line to ground surge energy couple into chip side, then capacitor and chip side TVS would discharge energy to ground."

In my understanding, we need TVS in between RJ45 and transformer because transformer simply has blocked the feature of surge discharging to ground. Does transformer really block surge discharging?

Appreciate if anyone here could help out to clear my confusion. Thanks a lot.

 

[FvM]

Unclear problem specifications bears unclear answers, I fear.

I agree that the "If ..." sentence doesn't make much sense. The transformer can be expected to block common mode surges but will pass differential mode surge, if occuring at all. The transformer capacitance passes a certain amount of fast surges, e.g. ESD events to the secondary, so clamp diodes might be still meaningful.