Hello, I am needing to create a 13 watt PoE power source, which eventually provides a 12VDC power rail to the PCB. I attached the schematic I currently implemented (see below). This is the "TPS2375" PoE controller

The problem with this is that I need isolation, since the device will have some connectors/plugs accessable to the end user. I am under the impression that the transformer/magnetics inside the RJ45 is not enough, and that I am supposed to put an isolation transformer in the mix, such as part number "POE13P-12" from coilcraft. The datasheet doesn't mention how to connect up a transformer. I don't think it matters if its flyback or forward transformer, I just simply need the isolation is all, but I can't find any information on this. I don't really know what I need to do here. Any help or advice is greatly appreciated.

And for reference, this is the RJ45 port I am using just in case that is needed: "HR873173A" from HanRun. It has magnetics built into the port.

 

What do you want to isolate from what?
The negative of your POE is ground.

 

What do you want to isolate from what?
The negative of your POE is ground.

The 48-52VDC coming from the POE also has POE ground. I need to take both of those and eventually have an isolated 48-52VDC and isolated ground, through some kind of POE isolation transformer (flyback, forward, etc.).

 

There are POE switch devices that also include a flyback converter driver, and suitable transformers available off the shelf. I’ll look up part numbers for you later -Analog Devices make them. I think that they are LT part numbers

 

LTC4267