Other Parts Discussed in Thread: UCC21520
Hi,
I have scaled up the reference Vienna design to run from a higher supply voltage, using Microchip/Microsemi Silicon Carbide mosfets as my switching devices.
This has been mostly successful so far, except for one issue:
I used the same gate driver devices as the demonstrator (UCC21520): in terms of the gate currents and switching frequency, they would seem to be suitable -
I did later see that other devices might be better suited for SiC but not particularly in terms of rating.
My problem is that the UCC21520's are getting excessively hot - not to the point of failure so far, but completely outside of what I'd expect (90°C surface temperature in a normal 20°C room ambient)
I have used the same FET's in a different application with a TI gate driver without any noticeable overheating
The Microsemi SiC FET's do, I later found out, strongly recommend a VGSon of 18-20V but I just copied the reference design and used a 15V power supply: I am consulting with Microchip as to whether this might stress the drivers, but I would like to know your thoughts on this or any other reasons the drivers might be running so hot, perhaps in terms of the particular Vienna application?
Many thanks
