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TPS23751: About PoE authentication

Part Number: TPS23751

Hi Team

Is there a time limit for detection and class identification?

There are voltage specifications in the data sheet, and as shown in the figure below, Detection is 2.7~10.1V and Classification is 14.5~20.5V.
Are there any time regulations for detection and class identification at this voltage?

best regards

TATSU

  • Hi TATSU,

    Thanks for reaching out.

    For 802.3 AT standard, classification time is 6-30ms per event (T_CLE). Max detection time (T_DET) is 0.5s. 

    Best regards,

    Diang

  • Hi Diang

    if possible could you also help me following question from customer?

    We believe that your response is an authentication event on the PSE side.
    What I would like to ask this time is whether there are time regulations on the PD side as well?

    best regareds

    TATSU

  • Hi TATSU,

    PSE is the signal sending side. PD is the signal receiving side which is relative passive during the detection and classification. I think PSE drives these hand shake signal timings. 

    From PD normally they are some comparators to sense the PD input voltage and decide turn on/off some voltage regulators / switches. 

    Best regards ,

    Diang