I have a PoE powered design, and it is currently equipped with magnetics not labelled as PoE, HX1188NL. There is also a transformer with a similar topology, HX2019NL.
However, the only difference I can see is the provided isolation.
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The non PoE one can stand 1650 V for 6 seconds.
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The PoE one can stand 1500 V for 60 seconds.
Apart from different isolation characteristics, what are the differences between non PoE and PoE transformers ?
Best Answer
PoE magnetics are designed to sustain also the DC currents that flow through the magnetics. You should not use magnetics which aren't marketed as PoE magnetics.
For example see coilcraft's
http://www.coilcraft.com/eth1-460.cfm
They're designed to comply with the IEEE PoE standard and are capable of sustaining a certain amount of wattage, in this case 60W but 13-25W magnetics are also common.
Normal magnetics may not be able to handle the DC offset currents during PoE operation.
Using 'normal' magnetics is probably asking for trouble.