Do I need calculate internal temperature of MOSFET based on surface temperature of PCB board?

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wanglipeng00000
Level 2
Level 2
10 questions asked 25 sign-ins 10 likes given
Hi, I am using MOSFET to control PMSM,and I have a question,Do I need calculate internal temperature of MOSFET based on surface temperature of PCB board?
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1 Solution
Abhilash_P
Moderator
Moderator
Moderator
50 likes received 500 replies posted 250 solutions authored

Hi,

   Thank you for posting on the Infineon community.

The case temperature or the drain pad temperature must be measured in order to get the junction temperature based on the following equation,

Tj - Tc / Rthjc = Pd

 

Regards,
Abhilash P

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3 Replies
Abhilash_P
Moderator
Moderator
Moderator
50 likes received 500 replies posted 250 solutions authored

Hi,

   Thank you for posting on the Infineon community.

The case temperature or the drain pad temperature must be measured in order to get the junction temperature based on the following equation,

Tj - Tc / Rthjc = Pd

 

Regards,
Abhilash P

wanglipeng00000
Level 2
Level 2
10 questions asked 25 sign-ins 10 likes given

Thanks,@Abhilash P,but I still don't know the equation,Tj - Tc / Rthjc = Pd,what does the means of Tj、Tc、Rthjc、Pd?

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Abhilash_P
Moderator
Moderator
Moderator
50 likes received 500 replies posted 250 solutions authored

Hi,

  Tj : Junction temperature
  Tc :  Case temperature
   Pd : Power dissipated. 
   Rthjc: Junction to case thermal resistance.

 

Regards,
Abhilash P