Voltage regulator and signal amplifying circuit

A voltage regulator, comprising:

• an error amplifier circuit, comprising:
• a first-stage amplifier, comprising:
• a first current source, coupled with a first power terminal;
• a fully differential amplifier circuit, coupled between the first current source and a second power terminal, and configured to amplify a difference between an output feedback signal and a reference signal to generate a first differential signal and a second differential signal;
• and
• a common mode feedback circuit, configured to provide a common mode feedback signal to the fully differential amplifier circuit so as to stabilize a direct-current common mode voltage of the first differential signal and the second differential signal, wherein the common mode feedback circuit comprises:
• a first amplifier circuit, configured to amplify a difference between the first differential signal and a common mode control signal to generate a first output current;
• and
• a second amplifier circuit, configured to amplify a difference between the second differential signal and the common mode control signal to generate a second output current,
• wherein the common mode feedback circuit is configured to generate the common mode feedback signal according to the first output current and the second output current;
• a second-stage amplifier, configured to amplify a difference between the first differential signal and the second differential signal to generate an output control signal;
• an output stage circuit, coupled with the first power terminal and comprising a switch, wherein the switch is configured to generate an output signal at an output node according to the output control signal;
• and
• an output feedback path, coupled with the output node and the error amplifier circuit, and configured to generate the output feedback signal according to the output signal.