A power switching circuit includes a power MOS transistor that has a
maximum source-drain voltage substantially higher than a permissible
gate-source voltage, and that has a current path connected in series with
a load between first and second supply terminals, and comprising a gate
driver circuit that drives the gate of the power MOS transistor directly
from the supply voltage. A gate driver circuit has a pair of
series-connected switching transistors connected between the first and
second supply terminals. An interconnection node between the switching
transistors is connected to the gate of the power MOS transistor. The
gate driver circuit further includes a reference voltage source and a
voltage comparator comparing the gate voltage of the power MOS transistor
with the reference voltage to provide a disabling output that disables
one of the switching transistors when the gate voltage of the power MOS
transistor reaches the reference voltage. By selecting a reference
voltage level not higher than the maximum permissible gate-to-source
voltage of the power MOS transistor, its gate is effectively protected
from excessive gate-to-source voltage. Yet, the switching transistor in
the gate driver circuit other than that connected to the ground supply
terminal (usually referred to as Vcc terminal), may have its current path
connected directly, or through just a feedback resistor, to the high
supply terminal (usually referred to as Vcc terminal).