• State
  • Locked Locked
  • Replies 2 replies
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 228 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

TPS548D21: Query on TPS548d21 Switch node pins connection to Inductor - Current density

seetaram reddy
Prodigy 30 points
Part Number: TPS548D21

We are currently performing  Power Integrity Analysis on the board.

I have a query on the TPS548d21 Switch node pins connection to Inductor - Current density

There are 7 switch node pins. The width of copper connection across the 7 Switch node pins is around 4mm.

Considering 2 oz copper of 70um, the total cross section is around 4*0.07 = 0.28 mm2.

Considering current of around 25A, the current density is around 89.28A/mm2.

 

As per IPC-2152, this will result in a temperature rise of around 70C which is definitely a serious concern.

Am I missing something? How to address this issue?

Would appreciate a prompt response.

  • 0
    TI__Guru**** 191445 points

    Seetaram,

    Yes the power density is quite high.  At 40 A output current you may see temperature rise of 75 deg. C.  At 25 A it should be lower.  Even not considering the copper trace, The IC itself, as well as the output put inductor, will contribute to the temperature rise.  for 25 A output, I would expect the temperature rise to be about 25 deg. C. less or about 50 deg. C.  This is based on measured thermal performance as shown in the datasheet.  Let me know if you have further questions.

  • 0 in reply to JohnTucker
    TI__Guru**** 191445 points

    Seetaram,

    Since you have opened a new thread on this topic I am going to close this one.