Patent ID: 7629783

Claim:
An ultra low dropout voltage regulator for low voltage conversion, comprising: a chip enable unit for controlling a bias voltage, supplied to drive internal circuits of a voltage regulator chip; a low reference voltage generation unit controlled by the chip enable unit and configured to set voltage and current to values within a predetermined range, or to generate the voltage and current; a pass element for receiving a voltage to be converted, passing only a stable voltage therethrough, and outputting the stable voltage; a feedback resistor for dividing the voltage output from the pass element, and feeding back a divided voltage to an error amplification stage; the error amplification stage controlled by the chip enable unit and configured to compare a reference voltage, output from the low reference voltage generation unit, and the voltage, fed back and output from the feedback resistor, and to amplify a difference between the output voltages, and smoothing an amplified signal; a gate drive stage controlled by the chip enable unit and configured to compare the output signal of the error amplification stage with the output voltage and to output a signal required to control the pass element in response to a control signal output from an overheat protection control logic; an overheat protection circuit controlled by the chip enable unit and configured to sense overload or overheat of the chip and to output a signal required to switch the output voltage; an overcurrent limiter controlled by the chip enable unit and configured to perform control to receive an input voltage and to output limited current through a logic interface; and the overheat protection control logic controlled by the chip enable unit and configured to receive the output signal of the overheat protection circuit and an output signal of the overcurrent limiter and to control the output signal of the gate drive stage.