DP83822I: Best PHY for TPS23881 POE PSE Implementation?

Hello Duncan,

If you are looking simply for a 10/100 base-T/TX PHY, I would like to recommend our DP83822, DP83825, DP83826 devices. What is your end application, and what reliability issues are you experiencing? What specific requirements for PoE are you trying to meet?

Sincerely,

Gerome

The attached schematic shows our implementation details. The issue we are having is random failures of the LAN8742A PHY (loss of E'net communication) which seem to be related to Ethernet cable connect/disconnect events to non-POE and POE devices. The POE-PSE implementation seems to be working fine. It's the PHY we're having issues with. The LAN8742A was inherited from a legacy design and if there is a better choice we have a pending design update coming on this board so now is the time to make a change if that will resolve theses issues.

Appreciate your help and any relevant reference designs that we could leverage.

Thanks - Duncan

POE Page from Schematic_10101.A_(ESDFixes-DRF-G)_2020-11-30.pdf

Gerome,

I think that we could squeeze the slightly larger 5x5 mm package of the PHYs you suggest into the space we have available (currently using a 4x4 mm PHY package). Are there smaller suitable TI options for the PHY?

Are there any reference designs for a POE PSE coupled with a PHY? The POE PD reference designs are useful but I hoping to find something that more closely matches our application.

Appreciate your help - Duncan

Hi Duncan,

The DP83825 would be the only PHY smaller that a 5x5 (its at a 3x3), but has a lower ESD rating compared to the DP83822/6. Because of this, I would recommend the DP83822/6.

I'll need to talk to the team to see if there is any other reference designs. I expect a result early next week.

Sincerely,

Gerome