There are many questions and answers regarding the value of the gate resistor, ranging from "anything will do" to "put something and see what happens". But even to put something and do experiments I need a footprint on the board, and I could not find anything on power rating for it.

Let's say the driver is powered by 32V and can supply 2.5A to the gate. That's a whole 80W. Often seen on the schematics 100 Ohm gate resistor will limit that to 320mA, which is still 10W. I've never seen 10W gate resistors though, so these primitive calculations must be wrong.

One idea is to use gate charge to get energy, then calculate slope and get time, then from energy and time get power and finally multiply it by frequency to get required resistor power rating. Sounds way too complicated, considering that most gate resistors I've seen were no larger than basic 0603 package.

So, how do I size the gate resistor?

There are many questions and answers regarding the value of the gate resistor, ranging from "anything will do" to "put something and see what happens". But even to put something and do experiments I need a footprint on the board, and I could not find anything on power rating for it.

Let's say the driver is powered by 32 V and can supply 2.5 A to the gate. That's a whole 80 W. Often seen on the schematics 100 Ω gate resistor will limit that to 320 mA, which is still 10 W. I've never seen 10 W gate resistors though, so these primitive calculations must be wrong.

One idea is to use gate charge to get energy, then calculate slope and get time, then from energy and time get power and finally multiply it by frequency to get required resistor power rating. Sounds way too complicated, considering that most gate resistors I've seen were no larger than basic 0603 package.

So, how do I size the gate resistor?