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TCA6424A: request thermal data

Part Number: TCA6424A

Hi,

I need below information for TCA6424ARGJR to our qualification team approval.

-      Junction Temperature Tj

-      Thermal Resistance RθJC

Regards,

TS

  • Hello TS Yang,
    I will have to put in a request to get the RthetaJC for the device. It will take a couple of weeks to get the information. We do not specify the max junction temperature, only the max operating ambient air temperature. I would assume that power dissipated in the device will be small and therefore the junction temperature will be very close to the max ambient air temperature. When do you need the information? I can probably get an estimate right away.
    -Francis Houde
  • Hello TS Yang,

    Well, good news.  It was already requested and the information is as follows:

    I will put it in my backlog to have it added to the datasheet.

    -Francis Houde

  • Hello Francis,

    thanks for your kind answer.

    I found below equation from datasheet.

    so, I understood about thermal data of TCA6424ARGJR as below.

    -      Max TA : 85c

    -      Calculated Max Tj = Max TA * (θJA*PD)

    -      Calculated Max Tj < Max TA

     Am I right?

    Also, I need one more information - Tc.

    Would you share the Tc(Case Temperature) of TCA6424A ?

    -TS

  • Hi Francis,
    Please let me know the Tc of TCA6424A first.
    thanks,
    TS
  • Hello TS,
    The case temperature of the device is to be measured along with the power dissipations (Pd) in the part. Once you have that information, then you can calculate the Tj of the part given the thermal resistance from case to junction. We specify the part operation of Ta, but it is referenced to a JEDEC standard. Our parts are simulated at 85C but technically our characterization data defines our guaranteed specifications. NOTE: characterization is done with minimal power dissipation so there will be a small temperature differential.
    Francis Houde
  • Hello Francis,

    As for the thermal data of TCA6424ARGJR, we finally need below parameters.

    Please check again the values.

    -       Tcase max

    -       Tjunction max

    -       RθJC

    -       PsiJT

     

    I feel sorry but please understand for the duplicated questions.

    thanks,

    TS

  • Hello TS,

    I already showed you the theta and phi parameters in the previous post in a table.  Tcase max isn't something we specify because this is a measured quantity.  Tjunction has to be extrapolated from the thermal resistances, the power dissipated, and the temperature of either air or case based on what you measure.  It must be calculated based on use case.  I am sorry, but I don't really understand what you need clarification with?  

    Here is a link to an app note specifying IC thermal metrics and how to use them:

    http://www.ti.com/lit/an/spra953c/spra953c.pdf

    http://www.ti.com/lit/an/slrr012/slrr012.pdf

    http://www.ti.com/lit/an/snva183b/snva183b.pdf

    Let me know what I can do to help clarify.

    -Francis Houde

  • Hello Francis,

    Sorry for your confuse, and really appriciate your sincere and quick reply.
    Above answers are good enough for me to fill in our quality materials.

    TS