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TPS7A45: TPS7A4501DCQT

samraj j
Prodigy 90 points
Part Number: TPS7A45

Hi Team,

We are using LDO TPS7A4501DCQT in one of our project our requirements is VIN - 13V Vout - 11.5 Iout - 1.5A our ambient temperature is 25°C to  50°C. In datasheet mentioned Junction-to-ambient thermal resistance - 50.5°C. If we are going to use Vout - 11.5 Iout - 1.5A at 50°C means we  are facing any thermal issues?

  • 0
    TI__Mastermind 37065 points

    Hello Samraj,

    With those values, and assuming a Tja thermal resistance of 50.5 C/W, the math works out to be the following:

    Junction Temp = Ambient Temp + (13-11.5)*(1.5)*(50.5 C/W) = Ambient Temp + 113.625 C

    If the ambient temperature is room temperature, then the junction temperature will be relatively hot at 139C.

    This will not violate the absolute maximum of 150C, but the lifetime of the part will be reduced.
    Additionally the component characteristics may fall slightly outside of the Electrical Characteristics tables, as they are only valid for temperatures at or below 125C.

    If you can use the larger KTT package, the thermal resistance will be 28 C/W and the temperature rise will just be 63C.
    This will yield a junction temperature (assuming ambient air temp of 25C) of 88C.

    Thanks,

    - Stephen