Fixed heatsink Zth

[Jed Wang_O]

Posted on March 20, 2018 at 15:09

[Alessio Corsaro]

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

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fields with thefour time constants (

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1= R1*C1,...,

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4=R4*C4).

You can also set a lower degree Foster model for the heatsink thermal impedance, filling the first R-

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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).