A voltage regulator includes an amplifier, a power device, a delay signal generator, and a voltage-generating circuit. The amplifier generates a control signal according to a reference voltage and a feedback voltage. The power switch generates the output voltage by regulating the output current according to the switch control signal. The delay signal generator generates a plurality of sequential delay signals each having distinct delay time with respect to an externally applied power-on burst signal. The voltage-generating circuit provides an equivalent resistance for generating the feedback voltage corresponding to the output voltage, and regulates the output voltage by adjusting the equivalent resistance according to the plurality of sequential delay signals.