• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 62 subscribers
  • Views 422 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.

POE Protection - TPS23851 - SEN4 pin fuse

Frank Weiner
Prodigy 60 points

Hello,

In the data sheet for TPS23851 (bottom of p12) , SEN4 pin is specifically refered to as needing a fuse to 'meet clearance safety regulations'.  Can you explain the issue?  What about SEN1-3 lines - same issue?  Thank you.

  • 0
    TI__Genius 9415 points

    Some equipment standards require certain creapage and clearance distance be maintained from high voltage to GND. The SEN4 pin which can be -48V is adjacent to the AGND pin of the TPS23851. If you have no such creapage and clearance specification to meet for your system, there is no need to do anything but direct wiring of SEN4 signal to the TPS23851 SEN4 pin. If you have such a requirement to meet, a fuse or a 20 ohm resistor in series with the SEN4 line will give the equipment protection from arcing. See your compliancee engineer and system specifications for appropriate actions for your equipment.

  • 0 in reply to Bob Kando
    Prodigy 60 points

    Thank you for your explanation.  Makes sense now.