TPS2376-H: TPS2376 PD controller failure for 802.af recognition

Alec Chen

Part Number: TPS2376-H
Other Parts Discussed in Thread: TPS2376,

Dear Sir,

Out Customer is using TI TPS2376 for their design and currently , they fail power up the TPS2376 PD controller. we have confirmed the the PSE side is ok(connect with other PD device and work fine) and the power muddle they use after TPS2376 (we could power up by sending individual power and enable). and the schematic look ok to us as well, Therefore, could you kinldy help us double check if there is anything that we miss or any suggestion for the issue. And here are their schematic and spec of some components that they use:

The schematic (removed)

Above, please help check and kinldy give us some suggestions. thanks in advance

Alec

over 4 years ago

0 Darwin Fernandez over 4 years ago

TI__Mastermind 40100 points

Hi Alec,

Looking at the schematic i only see one bridge, it might be that PSE is trying to power through the other pair sets. Can you confirm this?

Typically a PD design will have two bridges connected for each pair set.

0 Alec Chen over 4 years ago in reply to Darwin Fernandez

Intellectual 730 points

Dear Sir,

First. you are refering to the bridge shown as below, correct? we did checked with RD. They only use the 4 pair POE Pari12 and Pair36 . Do they still need the other set of bridge ? please kinldy let ue know. thanks

Above, please kindly hlep and if there is any other sugeesiton ,please feel free to let me know

0 Alec Chen over 4 years ago in reply to Darwin Fernandez

Intellectual 730 points

Dear Sir,

Above, please kindly hlep and if there is any other sugeesiton ,please feel free to let me know

0 Alec Chen over 4 years ago in reply to Alec Chen

Intellectual 730 points

Also, attach the schematic shown they ony use 4 pair (removed)

0 Alec Chen over 4 years ago in reply to Alec Chen

Intellectual 730 points

Correction: they are using " 2 Pairs" insetad of "4 Pairs". sorry for the typo error!

0 Artem Rogachev over 4 years ago in reply to Alec Chen

TI__Intellectual 1005 points

Hi Alec,

Darwin is out on business travel so I'll fill in while he is out. As Darwin said we typically recommend having 2 bridges, b/c you usually don't know what type of PSE your end equipment will get plugged into.

I took a quick look at the schematic and nothing obvious stood out with the exception of the diode bridge.

As the next step I would recommend taking a TPS2376H EVM and plugging it into your PSE. That would allow us to isolate if the issue is with TPS2376-H or the customer's design. If it's with the design we can start comparing to the EVM for any major differences.

Alternatively please ask the customer to share some waveforms with us.

Thanks,

Artem

0 Alec Chen over 4 years ago in reply to Artem Rogachev

Intellectual 730 points

Dear Artem,

Thanks for the help and now we are be able to power up the PD function. and i might need your kindly help remove schematic that we send earlier for the issue. the customer have a little concern about this schematic on the web. please kinldy help us with that. thanks in advance

Cheers

Alec