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TPS40055

eli
Guru 13485 points


How I can get Thermal Analysis for the TPS40055PWP?

  • 0
    TI__Genius 17240 points

    Hi Eli,

    The power dissipation of TPS40055PWP can be estimated as below:

    PT = (2 x Qg x fsw + IQ) x Vin, where Qg is the gate charge of the power MOSFET, fsw is the swiching frequency, IQ is the quiescent operation current of the TPS40055PWP, 1.5mA typical.

    The junction temperature then can be obtained:

    TJ = TA + PT x theta, where TA is the ambient temperature, thetaJA is the thermal resistance from junction to ambient, 38.3C/W.

    However, TJ might be overestimated using the above equation, because the PCB board is a huge heat sink.

    Another way to estimate the junction temperature is using the thermal characterization parameters listed on page 2 of the datasheet.

    TJ = TT + PT x PsiJT, where TT is the case top temperature, PsiJT is the junction-to-top characterization paramater, 0.4C/W.

    Regards,

    Na