Patent ID: 6979983

Claim:
A voltage regulator, to regulate a supply voltage and output a regulated voltage, the voltage regulator comprises: a two stage OP, wherein a first voltage and a second voltage are output according to a reference voltage and a feedback voltage, when the feedback voltage is raised, the first voltage is raised, and the second voltage is decreased; a voltage detection unit for detecting the supply voltage; a first regulating unit controlled by the voltage detection unit, receiving the second voltage and operated for outputting the regulated voltage when the detected supply voltage is in a high mode, when the second voltage is lowered, the regulated voltage is also lowered; and a second regulating unit controlled by the voltage detection unit, receiving the first voltage and outputting the regulated voltage when the detected supply voltage is in a low mode, the first voltage is raised, the regulated voltage is lowered; and a feedback circuit, receiving the regulated voltage for outputting the feedback voltage.