LMH5401-SP: Junction-to-case (top) thermal resistance

Kazuhiko Hirano

Part Number: LMH5401-SP

Hello,

Looking at LMH5041-SP datasheet, junction-to-case (top) thermal resistance (106.2 oC/W) is larger than junction-to-ambient thermal resistance (92.1 oC/W), this is very strange. Is this typo?
If so, how much is the true junction-to-case (top) thermal resistance?

Best regards,

K.Hirano

over 2 years ago

0 SimaJalaleddine over 2 years ago

TI__Mastermind 24355 points

Hi Hirano-san,

We will look into this issue, and get back to you by tomorrow.

Thank you,

Sima

0 SimaJalaleddine over 2 years ago

TI__Mastermind 24355 points

Hello Hirano-san,

It does look like this could be incorrect thermal resistance for the LMH5401-SP. I am submitting a thermal model request. Results usually take approximately 2 weeks.

Thank you,

Sima

0 Kazuhiko Hirano over 2 years ago in reply to SimaJalaleddine

TI__Genius 12828 points

Sima,

Thank you for your confirmation.
I look forward to receiving the correct junction-to-case (top) thermal resistance value in around 2 weeks.

Best regards,

K.Hirano

0 SimaJalaleddine over 2 years ago in reply to Kazuhiko Hirano

TI__Mastermind 24355 points

Hello Hirano-san,

Thank you for your patience. I received confirmation from the thermal team. The thermal resistance values are the same as the ones shown in the datasheet.

Explanation from the team:

"There is no contradiction between Rth-JC top of 106.2C/W and Rth-JA of 92.1 C/W. In this device, the die has very low thermal contact to the top lid of the package, thus Rth-JC top is high. The main cooling path of this device is toward the PCB which the Rth-JC bottom (63.8) is the proper parameter to use."

Thank you,

Sima

0 Kazuhiko Hirano over 2 years ago in reply to SimaJalaleddine

TI__Genius 12828 points

Sima,

I see, thank you for your confirmation.

Best regards,

K.Hirano

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LMH5401-SP: Junction-to-case (top) thermal resistance