TPS23756: Need clarification for APD & PPD

Miteshkumar Dalabhai Patel

Part Number: TPS23756
Other Parts Discussed in Thread: PMP40514, TIDA-00091,

Hi...team,

One of my customer is using TPS23756 for their application. They need clarification for APD & PPD connection.

For customer requirement, when AUX supply is present they need to disable PoE and enable it when AUX supply is absent. They are using the schematic circuit mentioned in this EVM attached here. Will this configuration work correctly for their requirement? or what should be the connection for PPD & APD pins?

Mitesh

TIDRBH4.PDF

over 1 year ago

0 Diang Xing over 1 year ago

TI__Mastermind 35471 points

Hi Mitesh,

Thanks for reaching out.

Normally APD is used to set PoE priority. Please see the TPS23756 related reference designs:

PMP40514

TIDA-00091

TPS23756EVM

Best regards,

Diang

0 Miteshkumar Dalabhai Patel over 1 year ago in reply to Diang Xing

TI__Intellectual 2390 points

Diand,

How to set the priority for my customer use case? What is the role of PPD pin & what connection shopuld be done in our case with PPD?

Mitesh

0 Diang Xing over 1 year ago in reply to Miteshkumar Dalabhai Patel

TI__Mastermind 35471 points

Hi Mitesh,

You can set PPD pin open to not use it. PPD is for low voltage passive PoE injector input.

In your case APD should help. Please check the reference design I listed.

Sorry that the PoE team has traveling and multiple works in list recently. Please expect a delay on the E2E reply.

Best regards,

Diang

0 Diang Xing over 1 year ago in reply to Diang Xing

TI__Mastermind 35471 points

Hi Mitesh,

You can set PPD pin open to not use it. PPD is for low voltage passive PoE injector input.

You can set APD in a voltage divider: when APD-RTN is higher than 1.5 V, the PD disables the internal hotswap switch, turns class off, and forces T2P active. This forces power to come from a external VDD1-RTN adapter.

Best regards,

Diang

Power management

Power management forum

TPS23756: Need clarification for APD & PPD