VOLTAGE REGULATOR

摘要

There is provided a voltage regulator that stably operates without using a large phase compensation capacitance. The voltage regulator has a voltage 3-stage amplifier circuit comprised of a differential amplifier circuit, a first source ground amplifier circuit provided with a phase compensation circuit, and a second source ground amplifier circuit, which serves as an output circuit. The voltage 3-stage amplifier circuit is provided, between the first source ground amplifier circuit and the second source ground amplifier circuit, with a phase compensation circuit that is effective for reducing the gains of the differential amplifier circuit and the first source ground amplifier circuit.

主权项

1. A voltage regulator comprising:
a reference voltage circuit that outputs a reference voltage; a voltage dividing circuit that outputs a feedback voltage obtained by dividing an output voltage; a differential amplifier circuit that receives the reference voltage and the feedback voltage and outputs a control voltage obtained by amplifying a difference between the reference voltage and the feedback voltage; a first source ground amplifier circuit that amplifies the control voltage output from the differential amplifier circuit; a first phase compensation circuit provided between an output terminal and an input terminal of the first source ground amplifier circuit; an output control MOS transistor constituting a second source ground circuit that receives a control voltage output from the first source ground amplifier circuit and controls the output voltage; and a second phase compensation circuit provided at a gate of the output control MOS transistor, wherein the second phase compensation circuit comprises: a sense transistor that passes a sense current based on a drain current of the output control MOS transistor; and a current mirror circuit that mirrors the sense current and passes the mirrored current to the gate of the output control MOS transistor.