• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 63 subscribers
  • Views 355 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPS23880: About monitoring MPS standard

Satoshi
Guru 19645 points
Part Number: TPS23880

Please let me confirm about monitor MPS for TPS23880.

PoE standard is described below diagrams, I want to know "MONITOR MPS" function.

Is above function monitoring at all times or certain timing? 

I think that monitor MPS process is below, is it correct?

⇒After PSE power supply to PD, PSE start to monitor MPS current at all time.

　If MPS current be less than 4.5mA or 6.5mA, or over TMPS+TMPDO time, PSE power supply will stop.

Best regards,

Satoshi

  • 0
    TI__Genius 15685 points

    Hi Satoshi,

    Your understanding is correct. The PSE monitors the current continuously. When the current falls below the the threshold, the MPS timer(TMPDO) starts. If the current keeps being below the threshold before time out, the PSE shuts off the port. Thanks.

    Best regards,

    Penny

  • 0 in reply to Penny Xu
    Guru 19645 points
    Penny-san

    Thank you for reply,

    Additional question for after TMPDO timer;
    When current keep being below and TMPDO time out, is TMPS monitor Ihold?

    I want to know which pattern for shut off below.
    ①Immediately TMPDO time out
    ②Need to period of TMPS after TMPDO time out

    Best regards,
    Satoshi
  • 0 in reply to Satoshi
    TI__Genius 15685 points

    Hi Satoshi,

    In order to keep the PSE port on, the current has to be higher than the threshold for longer than TMPDO + TMPS. I think TMPS is a fixed value(2.5ms typ and 3ms max). How the device sets the timer shouldn't impact the application level. Please see the datasheet note below.

    Best regards,

    Penny