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TMS320F28335: f28335 ΨJT

Joe Zhu
Intellectual 2540 points

Part Number: TMS320F28335

Hi Champion,

My customer want to test accuracy case to junction temperature, we have a parameter ΨJT in datasheet can calculate the case to junction temperature.

My question is :

1. Is this parameter influence by PCB structure? We do not have difference mark in it

2. How we test it, can you give me briefing for it?

Thanks!

  • 0
    TI__Mastermind 27240 points
    With increasing airflow, this is supposed to get lower if my understanding is right. Looks like we need to verify a few things. Some one of us should get back to you in a few days.
  • 0
    TI__Mastermind 42195 points

    Joe,

    To answer your first question:

    the heat transfer that is represented by Psi JT  is mainly heat transfer from the die through the bottom of the package and into the PCB. Then, of course, ambient air will cool the PCB. For that reason: Yes, PCB design will affect Psi JT. The quality of connection of the device to the PCB, the amount of copper under the device available to disperse the heat, as well as other nearby heat sources on the PCB will all play a significant factor.

    To answer your second question:

    I am not experienced in testing for Psi JT, but http://www.ti.com/lit/SPRA953 is a helpful resource.


    Regards,
    Cody