TPS566235: THERMAL METRIC of TPS566235 and TPS54625

Kento Sato

Intellectual 890 points

Part Number: TPS566235
Other Parts Discussed in Thread: TPS54625,

Hi team,

I have a question on THERMAL METRIC in datasheet.

In the data-sheet, RθJA is 70C/W for TPS566235, and that is 40.5C/W for TPS54625.

I think the definition of RθJA strongly depends on the board situation.

And TPS566235 is new device than TPS54625.

So could you tell me the measuring situation like board foot print and layer of these two device RθJA ?

-The measuring situation of TPS566235 RθJA (70C/W)

-The measuring situation of TPS54625 RθJA (40.5C/W)

Best regards,

Kento

over 4 years ago

0 Yuchang Zhang over 4 years ago

TI__Mastermind 18510 points

Kento,

70/40.5 should be based on JEDEC standard board. you can read SPRA953.

And also tps566235 provide EVM board data,

RθJA_effectiveJunction-to-ambientthermalresistancewith TI EVM----34.8

Yuchang

0 Michiaki Tanii over 4 years ago in reply to Yuchang Zhang

TI__Expert 4580 points

Hello Yuchang,

Looking at SPRA953 and EIA/JESD51-1 but I didn’t find the test board size and conditions.

Could you give us the each conditions for TPS562235 and TPS54625 ?

I simulated thermal performance with WEBENCH and found the large difference the theta ja from datasheet and simulation result.

I would much appreciate if you give us kindly explanation.

Thank you and best regards,

Michiaki

0 Gerold Dhanabalan - Online Design Tools over 4 years ago in reply to Michiaki Tanii

TI__Genius 14455 points

Hi Michiaki

The WEBENCH gives the effective theta JA based on the EVM layout size and the number of layers in the EVM.

We will get the JEDEC test conditions shortly.

Regards,

Gerold

0 Kento Sato over 4 years ago in reply to Yuchang Zhang

TI__Intellectual 890 points

Hi Yuchang,

Thank you for your support.

So do you mean these two devices' RθJA are evaluated in same situation and TPS54625 is lower than TPS566235?

Best regards,

Kento

0 Lishuang Zhao over 4 years ago in reply to Kento Sato

TI__Expert 7500 points

Hi Kento,

If you meaning

-The measuring situation of TPS566235 RθJA (70C/W)

-The measuring situation of TPS54625 RθJA (40.5C/W) ,

it is yes. They are based on same JEDEC, so the test situations are same.

JEDEC standard environment (JESD51-7 PCB) is based on 4 Cu layers (2oz, 1oz, 1oz, 2oc) and no thermal vias with 114.3*76.2*1.6mm board.

Thanks,

Lishuang

0 Kento Sato over 4 years ago in reply to Lishuang Zhao

TI__Intellectual 890 points

Hi Lishuang,

Thank you for your support.

I understand.

I have one basically question on JEDEC standard.

Should be all of competitor devices' datasheet RθJA in accordance with this JEDEC standard?

Best regards,

Kento

0 Lishuang Zhao over 4 years ago in reply to Kento Sato

TI__Expert 7500 points

Hi Kento,

I think we need to check case by case.

For example, one competitor's RθJA in datasheet is as below which doesn‘t based on JEDEC.

If competitor's RθJA is based on JEDEC standard, I think it should be same.

Thanks,

Lishuang

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TPS566235: THERMAL METRIC of TPS566235 and TPS54625