Hello team,
I received 2 questions from the customer.
Comparing LMR23630APDRRR and LMR23630AFDDAR, the thermal resistance is very different, why is the thermal resistance of LMR23630APDRRR very small?
Which is better to use to estimate the junction temperature, ψJT or ψJB? Could you please provide me with any material on thermal design?
Regards,
Masa
Hi Masa,
The reason why the package has better thermal performance is the amount of surface area there is on the die to something like a heatsink. The leads on the APDRRR variant are better for this.
For the better thermal junction variable, it depends on if what you are measuring. If you can obtain a thermal image of the top of the IC with a thermal camera, it would be simple to estimate the JT with ψJT. If you don't have either of those you can use this:
Please see this appnote for more information:
Thanks,
Andrew
