TPSM33625: Junction Temp

Brian Wang0928

Part Number: TPSM33625
Other Parts Discussed in Thread: LMR43620

Customer is doing the simulation on web tool. as a result, Tj data could be >100degree. It couldn't pass the design requirements.

Do you have any measured info. for reference? thanks.

Regards

Brian

0 Marshall_Beck over 1 year ago

Hi Brian, can you let me know the power conditions and provide the WB design parameters used?

0 Brian Wang0928 over 1 year ago in reply to Marshall_Beck

Condition: Tambient: 85度，Design's thermal derating = 80%，

Vin:21.6~26.4V

Vout:5V/1.23A

TJ < 100degree (Tj Derating with derating80%=> 125*0.8=100degree)

Simulation Result of the Thermal TJ is 97degree. it's closed to 100degree.

When current is in max current, it should be higher than 120degree.

0 Marshall_Beck over 1 year ago in reply to Brian Wang0928

Hi Brian,

We measured the case temperature as 101degC for the following condiiton:

24Vin, 5Vout, Load = 1.25A, Tamb=85degC

You are correct at max current it higher than 125degC and the application needs to derate.

If this doesn't work for your application, please consider LMR43620.

0 Brian Wang0928 over 1 year ago in reply to Marshall_Beck

Thanks.

In the LMR43620, the plot says the 55degree at 27degreeC ambient.

When 85degreeC ambient, it's already over 110degreeC, isn't? thanks.

+1 Marshall_Beck over 1 year ago in reply to Brian Wang0928

Yes, but LMR is rated for 150 junction and TPSM is rated for 125.

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