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TPS62130: Thermal Characteristics

Uma Sundaram
Prodigy 105 points
Part Number: TPS62130

Hi,

We are using TPS62130RGTR regulator for a Power Over coax application. Our output voltage is 3.3V with a current consumption of about 1.3A(Typ).This equates to power consumption of 4.29W.

The datasheet recommends  an Operating junction temperature, TJ of (-40 to 125)C and Junction-to-ambient thermal resistance (RθJA) of 45C/W [Pg5 of datasheet].

        On calculating the maximum junction temperature for our application using the expression, Tj = Ta + (Pd * RθJA) , we are getting a junction temperature of 193.05C, without  even considering the Ambient temperature(Ta).

This violates the Absolute Maximum Junction temperature of 150C specified in Pg5 of datasheet.

Can you please let us know if the TPS62130RGTR regulator can be used for the power required by our application (or) is any other device recommended for the design.

Your inputs are highly appreciated.

 

Thanks,

Uma

 

 

 

 

 

  • 0
    TI__Guru**** 150830 points
    Hi Uma,

    Assuming yours is an automotive application, we have the pin to pin TPS62130A-Q1 which is qualified for automotive applications. We also have the catalog TPS62130A, which offers a better PG pin behavior.

    Your Tj equation is correct, but the Pd term is just the power dissipated in the TPS62130 device. Your 4.29W is dissipated in your load, with the power dissipated in the TPS62130 being calculated from the efficiency of your circuit. Assuming your efficiency is 90%, for example, this is just 0.476W of loss with some of that being in the inductor (and not contributing to the IC temperature rise. Yes, TPS62130 is a good device to use here.

    Finally, note that the Theta JA listed in the D/S is just a JEDEC value based on a standard test board. Your Theta JA in a real application will likely be better/lower.
  • 0 in reply to Chris Glaser
    Prodigy 105 points

    Hi Chris,

        Thanks  for your reply.

    Regards,

    Uma