Tool/software:
Hello, Team
Our customer is currently considering to use TPS7B8250QKVURQ1 and would like to know the recommended spot with KVU package when they want to measure (a) Thermal Resistance between case-top and air (Rthca), (b) case-top temperature.
Could you please give us your guide on where to measure for each (a) and (b) with reasons? As of now, our customer thinks to measure the center o of the fin or package.
Best,
Masaru
Hi Masaru-san,
For you cannot directly measure RθJA (Junction-to-ambient thermal resistance), but you calculate it using the equation Tj = Ta + (RθJA * Power Dissipated)
Ta is the Ambient Temperature, Tj is the junction temperature.
You can calculate Tj using equation Tj = (Tc + ψJT * Power), where Tc is the case temperature, and ψJT is defined in the datasheet.
For case-top temperature, I would measure some where close to the middle of the package similar to below (marked in red).
The method to measure them is defined by JEDEC documents, and is described in the following document
https://www.ti.com/lit/an/spra953d/spra953d.pdf?ts=1738698944374
Let me know if you have any questions.
Regards,
Bobby
