Patent ID: 8736240

Claim:
A power system, comprising: (a) a power converter adapted for converting a first input voltage at an input thereof to a first output voltage at an output thereof; and (b) a hold-up time extension circuit comprising a step-up stage and a step-down stage coupled to each other via a first energy-storage capacitor, an input of the step-up stage being coupled to the input of the power converter, an output of the step-up stage being coupled to an input of the step-down stage, an output of the step-down stage being coupled to the input of the power converter; wherein the step-up stage is adapted for converting the first input voltage of the power converter to a second output voltage, and the step-down stage is adapted for converting the second output voltage of the step-up stage to the first input voltage of the power converter, and wherein the step-up stage maintains the second output voltage across the first energy-storage capacitor, and the step-down stage is activated when the first output voltage of the power converter is lower than a predetermined value.