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SN74ALVC244-EP: Junction to Case Thermal Resistance

Part Number: SN74ALVC244-EP
Other Parts Discussed in Thread: AM26LV32E-EP

What is the Theta JC for the SN74ALVC244IPWREP? I am interested in this value to calculate the temperature rise from the junction to the board.

  • Michael,
    I am in a discussion with our thermal modelling team. Theta Jc (bottom) is not normally provided for this package type.
    It is not considered directly applicable for devices without thermal pads that are physically contacting the board. I am requesting their advice, and will post back with more information.
    Can you describe how you intend to mount the devices to the board? Will there be air gap, or use of some thermal paste or adhesive?
    Regards,
    Wade
  • Michael,
    This should not be labeled as "TI thinks resolved" That was an accident.

    If you could provide information on how you would use the Theta Jc Bottom, then I can provide this to our modelling team for consideration. There is concern that use of this parameter (for devices without thermal pads) would lead to erroneous calculations. Please provide this information, and we can hopefully move forward with this request and your other thermal request for the AM26LV32E-EP.
    Regards,
    Wade
  • Wade,

    Theta JC (bottom) is probably not the right way to express what I'm looking for. I am trying to calculate Theta JB and have been calculating the resistance from the leads using the material and the drawing information. Therefore what I am really looking for is a Theta junction-to-lead; although, a Theta JB would be more useful if available.

    The plan is to not use thermal pads or paste unless it is needed. The hope is that the calculations will show that it is not needed.

    Please let me know if additional information is needed.

    Thank you,
    Mike

  • I have requested the generation of our standard model set, and it will include Theta JB.
    I will post here when complete.
    Regards,
    Wade
  • Wade,

    Any update on this?

    Thank you,
    Mike
  • Oddly enough, this completed just this morning.   I apologize, it was delayed because I did not get it submitted correctly.

    Here is the data.

    Theta JA-High K 97.9

    Theta JC, top   38.5

    Theta JB        49.5

    Psi JT           4.2

    Psi JB          49.1

    Regards,

    Wade