Thermal Analysis of SMPS

Thread Starter


Joined Feb 11, 2013
I built a simple 100W LED driver, I noticed the ambient temperature of the driver is increasing upto 80deg C after a few hours time. The MOSFET and Transformer are reaching up to 100deg. I am not sure if the temperature rise is within the acceptable range or not!
Can someone help?


Joined Aug 21, 2017
If mosfet outside is ca 100C then inside is ca 180C. Sure unpardoned.
Driver 80C outside is ca inside 140 C what is just on the sharp boarder between `to be or not to be that is the question`. If it would be the 60C it may be just brilliant.


Joined Feb 8, 2018
It really depends on the devices and how the supply is assembled.

80°C at the surface of the FET is probably OK. Again it depends on the device - what kind of package it is in. If the actual FET die in the package is at 100°C it will be just fine.

100°C is quite hot for a transformer but may be OK. It depends a lot on where the heat is being produced.