LM22676: Thermal parameters

Krzysztof Wiercioch

Prodigy 10 points

Part Number: LM22676
Other Parts Discussed in Thread: LP38852

Dear TI,

Is there possibility to get thermal characterization parameter (psi JT) to LM22676?

I tried to find this info in datasheet but without success.

Thanks!

over 1 year ago

0 Elena Gao over 1 year ago

TI__Genius 13735 points

hi，

I recommend to use Webench, you could input the condition and get a simulation result similar as below.

Elena

0 Krzysztof Wiercioch over 1 year ago in reply to Elena Gao

Prodigy 10 points

Hello,

Thanks for recommendation, but I'm looking for psi jt to calculate junction temperature using values from measurements (Tc).

0 Elena Gao over 1 year ago in reply to Krzysztof Wiercioch

TI__Genius 13735 points

hi,

please refer to this doc https://www.ti.com/lit/an/spra953c/spra953c.pdf?ts=1672814533031

Elena

0 Krzysztof Wiercioch over 1 year ago in reply to Elena Gao

Prodigy 10 points

Hi,

I'm referring to equation number 8 from that document

...and to perform calculation I need psi jt

0 Elena Gao over 1 year ago in reply to Krzysztof Wiercioch

TI__Genius 13735 points

Yes, you got it!

Elena

0 Krzysztof Wiercioch over 1 year ago in reply to Elena Gao

Prodigy 10 points

I found only general information... that "For plastic packages, ΨJT is typically 0.5°C/W–2°C/W".

General information is not always accurate.

For similar package /PowerPAD/DDA/8 - ΨJT can be more than 2°C/W". It's 9.6°C/W

e2e.ti.com/.../lp38852-psi-jt-and-psi-jb

So that's why I'm looking for more precise information for LM22676.

0 Elena Gao over 1 year ago in reply to Krzysztof Wiercioch

TI__Genius 13735 points

Thank you for you detail and update,looks this data meet calculation and webench result.

0 Krzysztof Wiercioch over 1 year ago in reply to Elena Gao

Prodigy 10 points

To which data you are referring to? I didn't see answer about ΨJT so far.

Should I assume that ΨJT of LM22676 is the same like for LP38852 since they are in the same PowerPAD 8 (DDA) package?

0 Elena Gao over 1 year ago in reply to Krzysztof Wiercioch

TI__Genius 13735 points

hi,

I haven't find a document or information for LM22676 , the ΨJT is almost same for same package ,but also have related to die size,

recommend to use around 8 to 10 °C/W .

Elena

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LM22676: Thermal parameters