TPS23754: TPS23754 no output

xiaowei chen

Part Number: TPS23754
Other Parts Discussed in Thread: TPS23861

Dear all:

TPS23754 no output when use PSE TPS23861 power supply, output normal use 48V power supply, the follow is the sch, please help check , thank you!

SCHEMATIC1 _ 32_LAN(I211).pdf

SCHEMATIC1 _ Page21_POE.pdf

over 6 years ago

0 Brett Colteaux over 6 years ago

TI__Expert 3700 points

Hi,

Thank you for your question. The PoE team is currently out of the office celebrating the U.S. holiday of Labor Day. Please expect a response on Tuesday, 9/3.

Thank you for your interest in Texas Instruments PoE devices.

Best Regards,

Brett Colteaux

0 Michael Pahl over 6 years ago

TI__Mastermind 21320 points

Hello,

Thank you very much for your question, and for providing your schematic. Can you additionally take a scope shot of VDD-VSS to capture detection, classification and startup?

Thank you!

Regards,

Michael Pahl

0 xiaowei chen over 6 years ago in reply to Michael Pahl

Intellectual 680 points

Dear Michael:

How to take a scope shot of VDD-VSS? thank you!

0 Michael Pahl over 6 years ago in reply to xiaowei chen

TI__Mastermind 21320 points

Hello,

You can measure it across C6 in your schematic. Thanks!

Regards,

Michael Pahl

0 Michael Pahl over 6 years ago in reply to Michael Pahl

TI__Mastermind 21320 points

Hello Xiaowei Chen,

We have not heard from you in almost a week. Do you have any update on this post?
I want to make sure you have everything you need to be successful on your project, but since we have not heard from you we will close this thread in a few days. Please let us know the status of your project and we can continue from there.

Thank you!

Regards,

Michael Pahl

0 Shiheng Huang over 6 years ago in reply to Michael Pahl

Prodigy 155 points

Dear Michael:

I am a hardware engineer,I have a project now using this chip,I want to know what will cause the detection to fail?And what should I do to solve this problem?Thanks!

0 Michael Pahl over 6 years ago in reply to Shiheng Huang

TI__Mastermind 21320 points

Hello,

Since this is a new question, I'd appreciate if we created a new thread to answer this question.

To answer your question, there is a large number of things that could cause detection to fail. I would need more information to give you a more accurate answer.

In general, I would first start by ensuring that the proper detection resistor is in place. Then I would capture the detection waveform and measure the detection current to get a picture of what is going on. If you could please provide these in a new post I can continue to support you in this issue. Thank you!

Regards,

Michael Pahl

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TPS23754: TPS23754 no output