PoE from 2 RJ45 LAN connectors (TPS23753 )

Mario Raffin

Other Parts Discussed in Thread: TPS23753, AM3352

Hi,

I am going to start a new design using the AM3352 which has two ports EMAC and the TPS23753 as PoE DC/DC converter. I wonder if there is a reference design in witch the power can be supplied from both the RJ45 connectors (not at the same time).

Thank you.

over 9 years ago

0 Darwin Fernandez over 9 years ago

TI__Mastermind 40100 points

Hello,

Do you have a high level diagram of your application? Do you mean two RJ45 in parallel? Thanks!

0 Mario Raffin over 9 years ago in reply to Darwin Fernandez

Expert 2355 points

Hi Darwin,
in my application I have two RJ45 with the AM335x which works as switch. Both the ethernet works at same time with data while only one of them receive power from PoE.

In principle I have to use two rectifiers (one for each port) a couple diodes (one for each port) before the DC/DC. It looks trivial I wonder if there is some side effect.

Below the diagram.

Regards,

mario

0 Darwin Fernandez over 9 years ago in reply to Mario Raffin

TI__Mastermind 40100 points

Hi Mario,

I haven't seen this type of setup before; however, I don't see an issue here. As you describe, only one port is powering the converter through the one PD at a time. That case is typical PoE.

Regards,

Darwin

0 Mario Raffin over 9 years ago in reply to Darwin Fernandez

Expert 2355 points

Darwin,

yes the solution seems to be straightforward. In principle, this setup does not cause trouble during the device classification.

thank you

mario

Power management

Power management forum

PoE from 2 RJ45 LAN connectors (TPS23753 )