TPS53219A: operating temperature range

Toshiro Imi

Part Number: TPS53219A

Hello,

Our customer has a question about operating temperature range. In his application, he measured the worst case temperature on package top raised up to 88.5C though the specification is guaranteed up to 85C TA. Even if this is not exceeded 150C Tj according to him, would you let us know if it has potential issue.

I simply think that some specifications may violate because TA is out of spec condition.

Best regards,

over 1 year ago

0 Tahar Allag over 1 year ago

TI__Mastermind 29410 points

Hello Toshiro,

The device junction temperature is 150C. having the case temperature at 88.5C, I am assuming your ambient is less than 88.5C, can you please confirm? you may still have a good margin to to reach the junction of 150C.

What is you wost case power losses and the ambient temps in you applications?

We can estimate the junction temps from that using the thermal metric below

Thanks!

Tahar

0 Toshiro Imi over 1 year ago in reply to Tahar Allag

TI__Expert 6350 points

Hello, Allag,

Thank you very much for our help.

We discussed how we can measure the ambient temperature in his test board. However the customer is annoyed ambient temperature measurement location.

Could you let us know which measurement point is the best, either the highest ambient temperature location, lowest or middle point even though the temperature gap may be not so much.

Best regards,

0 Tahar Allag over 1 year ago in reply to Toshiro Imi

TI__Mastermind 29410 points

Hello Toshiro,

focus on the point in where the temp is the highest just as shown below

Thanks!

Tahar

0 Toshiro Imi over 1 year ago in reply to Tahar Allag

TI__Expert 6350 points

Hi Tahar,

Thank you for your reply. The customer asked that he wants to know which location was the highest ambient temperature in your test case.

Best regards,

0 Tahar Allag over 1 year ago in reply to Toshiro Imi

TI__Mastermind 29410 points

Hello Toshiro,

To make sure that there is no confusion in the naming, ambient temp and is the outside temperature applied to the device. for example, if we are testing the device in the lab without airflow, than the ambient temp is the the lab room temperature.

case temperature if the the temperature measured using thermal camera and pointed at the center of the device as shown below

and than junction temperature can be estimated using the below equations

Junction Temp = Case Temp + Psi JT x Device Power

Note that Theta JC is NOT the right parameter to use for this analysis

For more details, check out the thermal application note here:

https://www.ti.com/lit/an/slua844b/slua844b.pdf?ts=1670871288652&ref_url=https%253A%252F%252Fwww.google.com%252F

Semiconductor and IC Package Thermal Metrics (Rev. C) (ti.com)

Thanks!

Tahar

0 Toshiro Imi over 1 year ago in reply to Tahar Allag

TI__Expert 6350 points

Thank you for your suggestion.
I fully agree with you that an ambient temperature should be a test condition, not measured on the board.
In this customer case, even though he does not disclose everything e.g. schematics, PCB layout, thermal source, I suppose that TPS53219A was located closely to the thermal source without enough heat sink. So I am wondering that the ambient temperature close to TPS53219A was higher than that. I think this is the reason he will measure the ambient temperature.
I will feedback to you his measurement data though, can we say that TPS53219A can guarantee the specification if his measurement results from less than 85C. can we also say that TPS53219A can guarantee the specification if Tj is less than 150C even if the ambient temperature is higher than 85C.

0 Tahar Allag over 1 year ago in reply to Toshiro Imi

TI__Mastermind 29410 points

Hello Toshiro,

The ambient temperature specifications are mentioned in the EC table and it is at 85C. The device still functional if the ambient is above 85C as long as the Junction is less than 150C. 88C is not too far from 85C, the EC table can still hold as the EC table did not account for the self heating of the device.

Thanks

Tahar

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TPS53219A: operating temperature range