TPS23754: TPS23754

Ronak Parmar

Part Number: TPS23754

Hi Sir,

We are using TPS23754 POE+ IC in our hardware design.

But when we use TP-Link POE (TL-SG1008PE OR TL-SF1005PV1 OR TL-SG1016PE) switch with TPS23754, internal hotswap mosfet getting shorted.

OK board impedance between RTN and VSS is 3ME.

After providing the POE supply from TP link switch it comes 10E.

Still that board is working with Tenda POE (POE15F)

Please support to narrow down this issue. We are getting field failure continuously.

over 3 years ago

0 Michael Pahl over 3 years ago

TI__Mastermind 21320 points

Hello,

Can you provide a schematic for review?

If this post answers your question, please indicate so by marking this thread as resolved. Thank you.

Regards,

Michael P.

Applications Engineer

Texas Instruments

0 Ronak Parmar over 3 years ago in reply to Michael Pahl

Intellectual 280 points

Hi Michael,

Thanks for the reply.

Please find the attached schematic for your reference. And let us know if any modification is required.POE+ schematic_Secured.pdf

+1 Michael Pahl over 3 years ago in reply to Ronak Parmar

TI__Mastermind 21320 points

Hey Ronak,

Our devices require a TVS diode on the VDD_VSS input rail. I see that you have two on the input pair sets. Unfortunately this is not equivalent, as a voltage surge can be generated from the secondary. Additionally, the TVS performance is critically dependent on the placement relative to the device it is protecting. When the TVS is electrically on the other side of the EMI choke it is no longer protecting the IC.

Therefore, we recommend adding a TVS between VDD_VSS. You could also add one across the pass FET for additional protection (VSS_RTN).

If this post answers your question, please indicate so by marking this thread as resolved. Thank you.

Regards,

Michael P.

Applications Engineer

Texas Instruments

0 Ronak Parmar over 3 years ago in reply to Michael Pahl

Intellectual 280 points

Hi Michael P.

Thanks for your valuable feedback. It has resolve our issue.

0 Michael Pahl over 3 years ago in reply to Ronak Parmar

TI__Mastermind 21320 points

Thank you for confirming! Glad to help.

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TPS23754: TPS23754