MOSFETs are getting better, year by year

I could show it to you privately, but we want to keep it secret as long as we can. We only plan to sell it to OEMs under NDA.

I'm driving SiC fets with GaN fets, which are in turn driven by the Tiny logic buffers, which are themselves driven by various things.

I blew up an impressive number of parts getting this to work. Learned a lot.

OK, John, thanks, I'm certainly not going to go to that much trouble to get an extra one or two ns of speed. I can appreciate, a little, how much work it is. What I found was that one blown part could take out an entire set of associated parts, and I really missed having my technician, ready to take over and replace the parts.

My scheme was to get everything working and then turn up the repetition rate, until failure. After it was clear I couldn't make 10MHz, I came up with the interleaved 5MHz approach.

One advantage to the BGA GaN fets is that I can't even think about soldering them myself. I send them to my magicians downstairs.

For production, we're putting the GaNs on little surface-mount castellated (mouse bite) baby boards, which become throwaway parts.

Those little fets are really fragile, like tiny glass bricks. We glob-top them to protect them and maybe improve the thermals a little. Once they are globbed, they are impossible to rework, so we don't want them on our main board.