CSD19536KTT: Theta_JA

Oba

Genius 17325 points

Part Number: CSD19536KTT
Other Parts Discussed in Thread: CSD16301Q2

Hello

I would like to know the condition of Theta_JA parameter in the datasheet of CSD19536KTT.

There is no information about that in the datasheet.

Also my customer would like to know Theta_JA parameter on 4-layer PCB for just reference.

I know Theta_jA highly depends on the environment, but do you have anything ?

Regards,

Oba

over 6 years ago

0 John Wallace1 over 6 years ago

TI__Mastermind 38200 points

Hi Oba,
Excellent question. There are additional resources available here: www.ti.com/.../spra953c.pdf & e2e.ti.com/.../understanding-mosfet-data-sheets-part-6-thermal-impedance. Let me check with the team to see if I can get additional details on how the TO220 theta_ja is tested.

0 John Wallace1 over 6 years ago in reply to John Wallace1

TI__Mastermind 38200 points

Hi Oba,

My mistake - I thought this was the TO220 packaged device. However, it is the D2PAK. I will get back to you with more information on thermal impedance of that package.

0 John Wallace1 over 6 years ago in reply to John Wallace1

TI__Mastermind 38200 points

Hi Oba,
Did the resources I pointed you to help to answer the question of how the measurements are made? I checked with a colleague and these measurements are made on a standard test card in free air. It's not possible to determine Rtheta(j-a) in an actual system without extensive testing and/or thermal modeling. Unfortunately, we don't have those capabilities at this time.

0 Oba over 6 years ago in reply to John Wallace1

TI__Genius 17325 points

Hello John,

Thanks for your reply. Could you tell me the specification of "standard test card" you mentioned in your reply?

Regards,
Oba

0 John Wallace1 over 6 years ago in reply to Oba

TI__Mastermind 38200 points

Hi Oba,
I checked with a colleague and the engineer is out until next week. I'll update when I get the information him. Some of our datasheets, such as CSD16301Q2 include some drawings of the min and max copper boards used for testing. This should be similar for the D2PAK device.

0 John Wallace1 over 6 years ago in reply to John Wallace1

TI__Mastermind 38200 points

Hi Oba,

Please see below.

TO-220s and D2PAKs RthJA is measured in free air.

Here is a picture of that measurement being done.

0 Oba over 6 years ago in reply to John Wallace1

TI__Genius 17325 points

Hi,

Usually, I think the test board for thermal data is usually JEDEC high-K or Low-K board.
Is that board different from these type of board?
And how many layer does this board have?

Regards,
Satoshi Obata

0 John Wallace1 over 6 years ago in reply to Oba

TI__Mastermind 38200 points

Hello Obata San,
Unfortunately, I don't have the detailed information on the board construction. We use the same setup for both TO220 and D2PAK thermal testing in open air. I checked some other manufacturers datasheet and they specify Rtheta(j-a) of 40C/W for a D2PAK mounted on a 1" square PCB (FR-4 or G-10 Material). This is the best information I have been able to find.

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CSD19536KTT: Theta_JA