Posted on March 21, 2018 at 11:23 Ciao Jed, thanks for your question!
The parameters in the red circle are related to the 4th degree Foster model fitting the heatsink thermal impedance (it is a RC network, as infigure 21 of the UM).
You have to fill the R fields with the R1,...,R4 values and the
https://wikimedia.org/api/rest_v1/media/math/render/svg/38a7dcde9730ef0853809fefc18d88771f95206c
fields with thefour time constants (
https://wikimedia.org/api/rest_v1/media/math/render/svg/38a7dcde9730ef0853809fefc18d88771f95206c
1= R1*C1,...,
https://wikimedia.org/api/rest_v1/media/math/render/svg/38a7dcde9730ef0853809fefc18d88771f95206c
4=R4*C4).
You can also set a lower degree Foster model for the heatsink thermal impedance, filling the first R-
https://wikimedia.org/api/rest_v1/media/math/render/svg/38a7dcde9730ef0853809fefc18d88771f95206c
couple (for 1st degree Foster model), the firsttwo
R-
https://wikimedia.org/api/rest_v1/media/math/render/svg/38a7dcde9730ef0853809fefc18d88771f95206c
couple (for2nd degree Foster model), or the first threeR-
https://wikimedia.org/api/rest_v1/media/math/render/svg/38a7dcde9730ef0853809fefc18d88771f95206c
couple (for3rd degree Foster model).
The thermal impedance you have set for the heatsink will be used to simulate the case temperature in all the steps (t1-t5 in your example).
