0
\$\begingroup\$

I have in my hand a AG9205s PoE PD module (output 5V and up to 13W) and I want to use it with my Raspberry PI 3B+ (that exposes the center core tap wires to the J14 pin header, as you can check here in the schematic)

Now comes my question: the AG9205s module shows that the external bridge rectifiers are needed as external part of the PoE PD module, as you can see here:

enter image description here

But at page 4 of the Datasheet, it says that the output of bridge rectifiers are connected to the respective internal pins, as shown below:

enter image description here

I'm a little bit confused...I've tried to connect the AG9205s module to the Raspberry Pi and works without any issue!

What am I missing? Are those bridge rectifiers inside the AG9205s module? Are they inside the LAN connector of the Raspberry? Do I need to add those rectifiers?

\$\endgroup\$

1 Answer 1

Reset to default
1
\$\begingroup\$

What am I missing? Are those bridge rectifiers inside the AG9205s module?

No, they are not inside - they are required in case the supply polarity coming down the ethernet line reverses or is reversed. You basically just got lucky when you tested it and happened to connect positive to the correct pin (1 or 3).

\$\endgroup\$
2
  • \$\begingroup\$ Thanks Andy, maybe i can use a pair of those DB207S (datasheet.lcsc.com/szlcsc/…) as input bridge rectifier? they can be suitable? \$\endgroup\$
    – VirtApp
    Commented Mar 11, 2021 at 14:00
  • 1
    \$\begingroup\$ I'd use a bridge compatible with this technical note. Note that schottky diodes are recommended @VirtApp. Also note that if there's data on those lines you need low capacitance diodes to prevent any likelihood of data corruptions. \$\endgroup\$
    – Andy aka
    Commented Mar 11, 2021 at 16:05

Not the answer you're looking for? Browse other questions tagged or ask your own question.