I'm a bit confused about how to drive a mosfet as a switch when dealing with high V_DS voltages. I have several nch mosfets with 100V+ up to about 1000V for max source to drain voltages.
I want to create a few buck converter circuits and others to test the quality of the output but I cannot for the life of me figure out how to drive the gates without requiring other high voltage components and without the circuit becoming overly complicated.
If you take a simple voltage diving circuit with the nch mosfet replacing the high-side resistor and try to drive the gate then the source terminal is "floating" in the sense that it depends on the load. If I tie the gate to the source through a resistor then this solves the problem by turning off the mosfet. Unfortunately it then causes major problems when trying to drive it. Not only that the gate then has to discharge through that resistor plus the low-side resistor, which here is the load, which reduces the fall time significantly for low loads.
One can't simply use another nch HV switch to connect the first mosfet's gate to ground because it brings the source of the first mosfet way below spec.
The issue is driving the gate so that it is only within +-20V of the source which can be up to several hundred voltages above ground almost up to Vcc.
Is there something I'm missing here? I imagine using a p-ch mosfet would be much easier yet I can't find ones with spec for my application yet N-ch's are abundant.