TPS54140A Thermal resistnce

taichi

Expert 1395 points

Other Parts Discussed in Thread: TPS54140A, TPS54140

Hello, team

TPS54140A's thermal information is drawed below in datasheet.

(DGQ PKG)

θja = 62.5 , θjctop = 83

(DRC PKG)

θja = 40 , θjctop = 65

They are shown θja > θjctop.

Is it correct?

over 10 years ago

0 JohnTucker over 10 years ago

TI__Guru**** 191445 points

That looks correct to me. Theta jc top should be high as almost all of the heat will transfer thru the thermal pad. I don't think that theta jc top is actually very useful. It is just included for completeness.

0 taichi over 10 years ago

Expert 1395 points

Hello, John

Thank you your reply.

My Customer said , Ambient Ra is higher than Theta Jc Calculated/Measured R.

It is wriiten by application note 'SPRA953' .

and

I check the TPS54140's datasheets. (same DGQ PKG of TPS54140A)

TPS54140 : θja = 67.4 , θjctop = 46.7

Which is correct TPS54140 or TPS54140A ?

Regards

0 Anthony F over 10 years ago in reply to taichi

TI__Mastermind 35185 points

I checked the original requests that these numbers were taken from and the TPS54140 is correct. The TPS54140A should have the same numbers.

0 taichi over 10 years ago in reply to Anthony F

Expert 1395 points

Hello,

I understand.

Will you have a plan to Rev. change of TPS54140A datasheet ?

Regards

Power management

Power management forum

TPS54140A Thermal resistnce