Good Day,

I am working on GAN FET from GAN System GS61008P and i want to calculate theoretical switching losses for my application. Unfortunately, there is no information regarding rise and fall time of transistor in datasheet from manufacturer. The only data i have is input/parasitic capacitance and gate resistance. So using this data i can calculate the time constant and i understand till here but using time constant of my FET how exactly can i calculate the rise and fall time of my GAN FET.
Thanks in advance

 

I have the same question. I suppose the simplified answer for calculating the rise time is multiplying the input capacitance (gate charge multiplied by the gate voltage) by the gate resistance. Is this right?

 

Many of the new FETs have not been tested for speed. Up to two months ago I could have tested them for you, but I can't now. I had two machines that dynamically tested transistors.

The data sheet does not have speed numbers because they have not been tested. I thought about using the SPICE models, but they will not be good for time for the same reason the data sheet is blank.

If you make a power supply with GAN parts your layout is very critical. It is easy to turn this transistor into a 300mhz power oscillator. I am willing to look over your schematic when you are ready.

 

Power Supply Design Notes: LTspice Simulations with GaN Devices - Power Electronics News
I wonder if spice derived data showing 96% efficiency is a reliable number without an actual test setup to find optimal parameters.