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MOSFET (Si/SiC) Forum Discussions

NXTY_Fujioka
Level 3
10 replies posted 10 questions asked First solution authored
Level 3
The RthJC of IPD65R190C7 is 1.73°C/W (max), but could you let me the Typ value of Rthjc?
I know it is difficult to answer with guaranteed values, so could you please give me some reference values?

By the way, the Rthjc specified in the data sheet does not change depending on the mounted board, right?
It is the recognition of Rthca that changes depending on the heat dissipation area of the mounted board.

Best regards,
Yuki Fujioka
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1 Solution
Pablo_EG
Moderator
Moderator 250 sign-ins 250 replies posted 25 likes received
Moderator
Hello Fujioka-san,

Thank you for posting on Infineon Forums.

There can be a very big deviation in the RthJC,typ values , based on different manufacturing locations, process deviations, soldering voids,... and therefore the RthJC can really go up to the RTHJCmax, which is defined and GUARANTEED in the datasheet.
Thus, Infineon strongly recommends using the RthJC MAX values.

I would like to let you know of a method for you to obtain a reference (NOT GUARANTEED) Typical RthJC.
You can download the CoolMOS 650V SPICE library from here:
https://www.infineon.com/cms/en/product/power/mosfet/500v-900v-coolmos-n-channel-power-mosfet/650v-a...

Once you extract the library, you can open it by using Notepad (メモ帳).
You can look for your part number by pressing Ctrl+F and inserting the model number.
Go to the L3 model as shown here:
5193.attach

The five resistances highlighted are the full RthJC.
By adding the minimum values, we can obtain the average RthJC.
In the case of IPD65R190C7, it would be 29.7m+40.97m+229.91m+290.77m+214.49m = 0.8 °C/W

Please remember that this value should not be taken as an absolute value and should not be used when designing an application.

Regarding your second question, your understanding is right.
The Rthjc shown on the datasheet is independent of the heatsink or mounting board that is being used.

Let me know if this method is helpful for you.

Best regards,
Pablo

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Pablo_EG
Moderator
Moderator 250 sign-ins 250 replies posted 25 likes received
Moderator
Hello Fujioka-san,

Thank you for posting on Infineon Forums.

There can be a very big deviation in the RthJC,typ values , based on different manufacturing locations, process deviations, soldering voids,... and therefore the RthJC can really go up to the RTHJCmax, which is defined and GUARANTEED in the datasheet.
Thus, Infineon strongly recommends using the RthJC MAX values.

I would like to let you know of a method for you to obtain a reference (NOT GUARANTEED) Typical RthJC.
You can download the CoolMOS 650V SPICE library from here:
https://www.infineon.com/cms/en/product/power/mosfet/500v-900v-coolmos-n-channel-power-mosfet/650v-a...

Once you extract the library, you can open it by using Notepad (メモ帳).
You can look for your part number by pressing Ctrl+F and inserting the model number.
Go to the L3 model as shown here:
5193.attach

The five resistances highlighted are the full RthJC.
By adding the minimum values, we can obtain the average RthJC.
In the case of IPD65R190C7, it would be 29.7m+40.97m+229.91m+290.77m+214.49m = 0.8 °C/W

Please remember that this value should not be taken as an absolute value and should not be used when designing an application.

Regarding your second question, your understanding is right.
The Rthjc shown on the datasheet is independent of the heatsink or mounting board that is being used.

Let me know if this method is helpful for you.

Best regards,
Pablo
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NXTY_Fujioka
Level 3
10 replies posted 10 questions asked First solution authored
Level 3
Dear Pablo

Thank you for your answer.

I could understand that I can learn about Rthjc by referring to the Spice model.
I will be careful not to design with this Rthjc as you mentioned.
I also understood that Rthjc in the data sheet is a parameter that is not affected by PCBs, etc.

This thread has been solved.
Thanks.

Best regards,
Yuki Fujioka
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