Limiting high current, low voltage

[Marco]

If you are worried about noise forget about synchronous buck, just use a regular buck. For instance with one of these.

If you are designing a high current buck converter some extra supply voltages to efficiently drive the MOSFET shouldn't even be on the radar. just use modules if you don't want to spend the time (bucking from relatively low voltage a bootstrap circuit in a driver or controller might not be enough, if you want 10V gate drive 5V input won't get you there).