• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 63 subscribers
  • Views 215 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.

TPS23881: TPS23881 detection resistance out of range

Zhizhao Niu
Expert 4400 points
Part Number: TPS23881

Hi team,

Here I have a question on PSE chip TPS23881. For the detection resistance out of range, if the detected resistance is at the range of 15K~19k, which is lower than the accepted range and higher than the Rejected low range, which status will reported in the DETECTn register?

 

 

B.R.

Lucas

 

  • 0
    TI__Genius 15685 points

    Hi Lucas,

    Our FW sets the acceptance range to 17K ~ 29K.  You can also find the tested detection range from sifos report here. Thanks.

    Best regards,

    Penny

  • 0 in reply to Penny Xu
    TI__Expert 4400 points

    Hi Penny,

    Thank you for your reply, I am not very familiar with PoE. Could you please explain in more detail what the state of DETECTn register should be when the detection resistance is 15k~19K ?


    B.R.

    Lucas

     

  • 0 in reply to Zhizhao Niu
    TI__Genius 15685 points

    Hi Lucas,

    The data in the table is from  IEEE spec, and there is some grey area(15K to 19K and 26.5K to 33K) not being defined. These grey area is up the PSE vendors' decision. Our PSE devices(TPS238x family) define the Rhigh(29K to 100K), Rlow(0.86K to 17K), Rvalid(17K to 29K).

    So to answer your question, 15K to 17K is Rlow, 17K to 19K is Rvalid. Thanks. 

    Best regards,

    Penny