Tj temperature calculator for fets

Free standing Heatsinked

A
°C
°C/W
°C/W
°C/W



°C
This calculator will calculate the internal Tj of a mosfet.
RdsON is the resistance the mosfet will have when fully on.
It is adviced to use worst case figures.

Ambient is the ambient temperature the mosfet will be in.

RθJA can be found in the datasheet. It's the temperature
difference between the junction and ambient. Similarly JC and CA
stands for Junction to case, and case to air, where case to air
is to be found in the datasheet for the heatsink.