Patent ID: 6885238

Claim:
A method of providing a plurality of supply voltages from a variable input voltage applied to a semiconductor device during a plurality of periods, the method comprising the steps of: providing a plurality of voltage control elements; establishing a first voltage control signal from the voltage control elements; generating a first supply voltage from the first voltage control signal, the first supply voltage being responsive to variations in the input voltage below a first voltage clamping level determined by the first voltage control signal, the first supply voltage being clamped when the input voltage increases above the first voltage clamping level determined by the first voltage control signal; reversibly bypassing at least one of the plurality of voltage control elements; establishing a second voltage control signal from the plurality of voltage control elements which are not reversibly bypassed; generating a second supply voltage from the second voltage control signal, the second supply voltage being responsive to variations in the input voltage below a second voltage clamping level determined by the second voltage control signal, the second supply voltage being clamped when the input voltage increases above the second voltage clamping level determined by the second voltage control signal; irreversibly bypassing at least one of the plurality of voltage control elements; establishing a third voltage control signal during a third period from the plurality of voltage control elements which are not irreversibly bypassed; and generating a third supply voltage from the third voltage control signal, the third supply voltage being responsive to variations in the input voltage below a third voltage clamping level determined by the third voltage control signal, the third supply voltage being clamped when the input voltage increases above the third voltage clamping level determined by the third voltage control signal.