Patent ID: 8102163
Filing Date: 2012-01-24
Classification: G05F

Abstract:
1. A voltage regulator, comprising: an input terminal; a ground terminal; an output terminal; an output transistor provided between the input terminal and the output terminal, for generating an output voltage based on an input voltage and a gate voltage; a voltage divider circuit provided between the output terminal and the ground terminal, for dividing the output voltage to output a divided voltage; a reference voltage circuit for outputting a reference voltage; a first amplifier including a first input terminal provided at an output terminal of the reference voltage circuit and a second input terminal provided at an output terminal of the voltage divider circuit, for controlling the output voltage to a desired constant voltage; a second amplifier including an input terminal provided at an output terminal of the first amplifier and an output terminal provided at a gate of the output transistor; a resistor; a third amplifier including an input terminal provided at the output terminal of the first amplifier through the resistor and an output terminal provided at the gate of the output transistor, for providing push-pull output in cooperation with the second amplifier; and an auxiliary circuit provided at a connection point between the resistor and the input terminal of the third amplifier, for detecting a ripple and operating the third amplifier based on the ripple.