TPS23754 / APD detection

Ryuji

Guru 20090 points

Other Parts Discussed in Thread: TPS23754

Hello,

Does the PSE stop the power supply if the TPS23754 detect the Adapter input ?
I would like to know the PSE operation on the Adapter input.

I think that the CLS output will be disabled if the TPS23754 detect the Adapter input at the APD pin.
Then the PSE device will be off.

Best Regards,
Ryuji Asaka

over 8 years ago

0 Eric Wright over 8 years ago

TI__Mastermind 42795 points

If the APD pin goes above 1.5V (due to an installed adapter), then TPS23754 CLASS regulator is disabled and the connection to the PSE is open (TPS23754 VSS-RTN MOSFET is OFF). After 300-400ms, the PSE will detect the disconnection and remove power from the port.

0 Ryuji over 8 years ago in reply to Eric Wright

Guru 20090 points

Hello Eric san,

Thank you for the reply. I understood that the PSE remove power from the port when the PSE detect the disconnection.
Could you please let me know the 300~400ms reason? I couldn't found this information from the datasheet.

Best Regards,
Ryuji Asaka

0 Eric Wright over 8 years ago in reply to Ryuji

TI__Mastermind 42795 points

Page 21 of the TPS23754 datasheet describes the PD side responsibility for MPS (Maintain Power SIgnature) but not the PSE end MPS (Tmpdo in the IEEE 802.3at-2009 standard).

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TPS23754 / APD detection