TPS709: Thermal resistance of TPS709 in DBV package

JosefMieslinger

Part Number: TPS709
Other Parts Discussed in Thread: TLV704,

Dear TI-Team,

we evaluated TLV704 and TPS709 in SOT23-5 (DBV) package for an industrial application.
According to the datasheets TPS709 has about half the thermal resistance (junction to case, junction to board), in the same package compared to TLV704.

Can you please explain why there is this difference despite using the same package.

Thanks and best regards,
Joe

over 7 years ago

0 Ryan Eslinger over 7 years ago

TI__Guru 55940 points

Hi Joe,

There are a variety of factors that impact the thermal performance of a device including leadframe, die size, die placement, mold compound, and more. While the type of package has a large impact on thermals, due to the other factors, there can still be a large variation between two devices.

Very Respectfully,
Ryan

0 Alexander Seufert over 7 years ago in reply to Ryan Eslinger

Prodigy 20 points

Hello Ryan,
thank you for this Information,
but why is R_th Junction to Ambient more ore less the same, but R_th junction to board is only 50%

0 Alexander Seufert over 7 years ago in reply to Ryan Eslinger

Prodigy 20 points

Hello Ryan,

thank you for your answer.
But I do not understand why is R_th Junction to Ambient more ore less the same, but junction to case and junction to board is only 50%.
Thank you
Best Regards
Alex Seufert

0 Ryan Eslinger over 7 years ago in reply to Alexander Seufert

TI__Guru 55940 points

Hi Alex,

It comes down to the fact that these are two different measurements for two different devices. Both devices with all of the influencing are similar in how they dissipate heat into ambient free air; however, TPS709 is better able to dissipate into the board.

Very Respectfully,
Ryan

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TPS709: Thermal resistance of TPS709 in DBV package