Patent ID: 7692976

Claim:
A method for operating a controller that includes at least a first circuit arrangement and a second circuit arrangement, the method comprising: the controller receiving power from a power supply, via a positive power rail and a ground power rail having a first differential supply voltage there between; the controller receiving a control signal; in response to the control signal indicating a first state, the first circuit arrangement of the controller providing the first differential supply voltage at a differential output of the controller; in response to the control signal indicating a second state, the second circuit arrangement of the controller: generating a second differential supply voltage from the first differential supply voltage, wherein the second differential supply voltage is less than the first differential supply voltage; and providing the reduced second differential supply voltage at said differential output of the controller wherein the first circuit arrangement providing the first differential supply voltage includes: a first device in the first circuit arrangement providing charging current to a switching device in the first circuit arrangement; the switching device, responsive to the control signal indicating the first state, providing a voltage of the ground power rail to a non-inverting buffer; and a second device, coupled to an output of the non-inverting buffer, providing a voltage of the positive power rail to the differential output of the controller.