TPSM5D1806: TPSMD5D1806 : Thermal Resistance Parameters

Part Number: TPSM5D1806

Tool/software:

Hi,
I am planning to use the TPSM5D1806RDBR buck converter in my new design. I need the thermal resistance values for junction-to-case (top and bottom) and junction-to-board. I found these values in your forum, but it was mentioned that they are based on simulation data. Could you please confirm if there would be any differences in real measurements? If so, what margin of variation should be expected between simulation and actual data?
The values I noted from the forum are:
  1. Junction-to-case (Top): 14.6 °C/W
  2. Junction-to-case (Bottom): 2.5 °C/W
  3. Junction-to-board: 4.6 °C/W
Kindly review and provide your feedback.
  • The document http://www.ti.com/lit/SPRA953   explains how these metrics are measured, their applications, and limitations. It emphasizes that RθJA is often misused and should not be directly applied to estimate junction temperatures in real systems. The note introduces ΨJT as a more practical metric for estimating junction temperatures from measured case temperatures. It also covers factors affecting thermal performance such as PCB design, die size, package configuration, and altitude. The document includes measurement procedures, equations, and practical considerations for thermal management.