I am trying to better understand high side switching with N channel mosfets using discrete components. The problem I am running into is as follows: In what I understand to be the standard bootstrap configuration like in the picture below, the voltage from the gate to the source of the power mosfet is always about equal to the supply voltage. If I am trying to use a supply voltage higher than what the mosfets gate to source rating can handle, like above 20V ish, I blow up the fet... My initial thoughts are to use a zener to drop the voltage after R1, or to add a smaller resistor from R1 to ground to act as a voltage divider. I feel like both of these solutions are pretty crap simply because of the power losses associated with them and the large components they would require to work out... Im not willing to accept using a higher value resistor for R1 because I want to still be able to switch at high speeds, preferably above 40khz or so eventually. I am also trying to avoid the addition of another isolated power supply, as I would like everything to have a common ground... Gate drive transformers are also out of the question. Anybody know how this is done without IC's in real life? Thanks!