Patent ID: 8593123

Claim:
A voltage regulator, comprising: an output stage having an inductor, an output capacitor, a first transistor coupled between an input port and a swinging node, and a second transistor coupled between the swinging node and a circuit ground, said first and second transistors arranged to switchably direct currents through said inductor and said output capacitor to thereby generate an output voltage across said output capacitor; and a controller, including a hysteretic comparator and a pulse-width modulation (PWM) comparator, said controller having at least first and second operational modes, wherein in the first operational mode, the controller is operable to switch said first and second transistors according to an output signal from said PWM comparator, said output signal based on an error voltage that indicates a difference between said output voltage and a predetermined voltage, and in the second operational mode, said controller is operable to turn off said PWM comparator and turn off switching of said first and second transistors when the magnitude of said error voltage drops below the magnitude of a first threshold voltage and return to said first operational mode, in response to a turn-on signal from said hysteretic comparator, when the magnitude of said error voltage rises above the magnitude of a second threshold voltage.