I'm looking for any advice that can be given to solve this issue. I followed the design idea from here: buck regulator to CC source and it appears to work pretty well until I started raising the load resistance. 1Ω-2Ω works great, above 2Ω the current starts to fall off.
I first thought I was running out of head room, but with a 45V input the output voltage is only reaching about 30V. I would think that the output voltage should be able to get much closer to the input voltage.
Any ideas on what to check? Thanks!