Patent ID: 7768214

Claim:
A step-up/down regulator circuit that steps up or down an input voltage to generate a desired output voltage, the step-up/down regulator circuit comprising: a first switch whose first end is connected to an input voltage input terminal; an inductor whose first end is connected to a second end of the first switch; a second switch whose first end is connected to a second end of the inductor, whose second end is connected to a standard voltage input terminal, and whose control end is connected to the second end of the first switch; a third switch whose first end is connected to the second end of the first switch, and whose second end is connected to the standard voltage input terminal; a fourth switch whose first end is connected to the second end of the inductor, and whose second end is connected to an output voltage terminal; a capacitor whose first end is connected to the output voltage terminal, and whose second end is connected to the standard voltage input terminal; feedback voltage generating circuitry for generating a feedback voltage according to an output voltage at the output voltage terminal; an error amplifier for amplifying and outputting a difference between the feedback voltage and a predetermined reference voltage; and switch control circuitry for receiving an output from the error amplifier and for opening and closing the first switch so as to reduce an amplitude of the output from the error amplifier, and, complementarily thereto, opening and closing the third and fourth switches.