Announcements

Live Webinar: Solving the challenges in xEV power conversions | March 7 @9am & 5pm CET. Register now!

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
yjc0101
Level 1
Level 1
5 replies posted 5 questions asked 10 sign-ins

HI.

As shown in the figure below, I would like to know how the 30A current is calculated for the IAUC120N06S5N017 at T a=85 °C, VGS=10 V,RthJA on 2s2p2,4)? Thank you.

yjc0101_0-1688464993459.png

 

0 Likes
1 Solution
Abhilash_P
Moderator
Moderator
Moderator
50 likes received 500 replies posted 250 solutions authored

Hi,

   Usually for practical considerations we take Tj to be 150C.

Hence recalculating Id for this Tj comes to be around 32A which can be approximated to 30A. 

 

Regards,
Abhilash P

View solution in original post

0 Likes
4 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 Id = 30A at Ta = 85C is calculated as below,

Step 1: Calculate Ptot at Ta = 85C

Ptot = (Tj - Ta ) / Rthja
         =  (448.15 - 358.15)/23.3
         = 3.862W
(Here Tj is 175C and Ta is 85C which is converted to Kelvin scale since Rthja is in K/W)

Step2: From Ptot we calculate Id

Ptot = Id^2 * Rdson 

Id = sqrt ( (Ptot / Rdson) )
     =  sqrt (( 3.86 / 2.5m))
     =  39A 
     = approximately equal to 30A ( this is verified by practical measurements )

 

 

Regards,
Abhilash P

0 Likes

HI. Abhilash_P .

According to your reply, the final result is 39A is approximately equal to 30A, the error of this approximation is a bit too large, right?The RDS of MOS tube is compensated according to 2.5mΩ, according to the curve of Figure 8 Typ. drain-source on-state resistance in the manual. The TJ used for the calculation is calculated according to the 175 ℃? Or according to 150 ℃ or other allowances with a certain margin? If TJ needs to leave a margin, what is the approximate margin?

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

Hi,

   Usually for practical considerations we take Tj to be 150C.

Hence recalculating Id for this Tj comes to be around 32A which can be approximated to 30A. 

 

Regards,
Abhilash P

0 Likes

Thank you for your reply.Abhilash P.

0 Likes