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MOSFET (Si/SiC) Forum Discussions

NXTY_Fujioka
Level 4
Level 4
5 solutions authored 25 sign-ins 10 replies posted

Hi all,

I want to simulate the Tj of a MOSFET by reading the actual measured VDS and IDS switching waveforms using LTSpice.
The Infineon IGBTs have a description of the RC thermal model in the datasheet and can be simulated using this value, but CoolMOS and Optimos do not have this information and cannot be simulated thermally.

NXTY_Fujioka_0-1673514349397.png

However, I look at the lib files provided on the web, I see the RC thermal model.
For example, IPB027N10N3 would correspond to the part in the red box below.

 

NXTY_Fujioka_2-1673515429363.png

If I could extract this parameter, it would be possible to perform thermal simulation with VDS,IDS with real waveforms as well as IGBTs, but is it possible to extract only this parameter?

If there is a better way, I would appreciate it if you could let me know.

 

Regards,

Yuki 

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2 Replies
TakashiO
Moderator
Moderator
Moderator
100 sign-ins 50 replies posted 25 solutions authored

Dear @NXTY_Fujioka,

Thanks for posting your questions on this community.

Yes, you can use the Rth and Cth parameters for your original thermal simulation. The parameters are defined for Cauer model(The Rth and Cth in IGBT product are defined for Foster model).

Please find the following document in detail. Fig.2 in the document represents the internal model of the Spice file.

 Dynamic thermal behavior of MOSFETs(AN_201712_PL11_001 )

Thank you

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TakashiO
Moderator
Moderator
Moderator
100 sign-ins 50 replies posted 25 solutions authored

Dear @NXTY_Fujioka ,

When you use the parameters in your own simulation, please replace "limit(Zthtype,0,1)" to "1". Then you can get each Rth and Cth value for the Cauer ladder. 

Thank you

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