LTC3780 : Back to square one, and now it works
After frying and fixing again the LCT3780 (feedback loop broken, one more time), i realized the current limiting is somehow flawed. Here is the schematic of the original CC : The problem is that the feedback (0.8v) is the sum of Isense and Vout * Pot So the current limiting is not accurate and depends on Vout. Let's change that, so that only one is used : Voltage or Current mode. It means the biggest of Vout or Isense is taken into account and the other one is ignored. Biggest of 2 voltages: it means diodes. To do that we'll remove the 14k resistor on the board And cut the track on the other side (cut at the white mark ) Let's add a very small circuit instead : We'll have a slight offset generated by the shottky diode (~ 200 mv in my case), but it's constant, it does not matter much. That becomes (with the usual craftmanship): The output of that small circuit will be connected to the pad of the 14k resistor we just removed (the p