TPS23756: TPS23756 cannot startup , but when use a probe, it can startup again.

Frank Xiao

Genius 12055 points

Part Number: TPS23756
Other Parts Discussed in Thread: TPS23861

Hi team,

My customer is using the TPS23756 now 12v 2A. They find one board cannot startup with PSE(switch). We want to try to test what's the condition, then we use a probe for the POE_VDD and VSS. The board can start up. Do you have some experience about the phenomenon? Thanks.

over 4 years ago

0 Thomas Lewis over 4 years ago

TI__Expert 5615 points

Hi Frank.

Do you have any additional information you can share on the load side (manufacturer, model, IC)?

Does the vendor have the PoE logo?

Thanks for your local support,

0 Darwin Fernandez over 4 years ago in reply to Thomas Lewis

TI__Mastermind 40120 points

Hi Frank,

I have seen issues similar to this in the past with non-isolated PSEs. As Thomas suggested, it is highly likely the PSE. Have you tried with different PSE, like TPS23861EVM with bench power supply and no probing the PD to see if it passes? But to make sure it is not the PD design, can you forward the schematic of the PD design (including the PD front end circuits)?

Thanks!

0 Frank Xiao over 4 years ago in reply to Darwin Fernandez

TI__Genius 12055 points

Hi Darwin,

We will apply a TPS23861 EVM for the customer first. The PSE side is a switch below. Thanks.

0 Darwin Fernandez over 4 years ago in reply to Frank Xiao

TI__Mastermind 40120 points

Thanks Frank! we can look into the PSE, please let us know how their testing with the EVM goes. Thanks!

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TPS23756: TPS23756 cannot startup , but when use a probe, it can startup again.