Amplifier circuit for microphone, microphone circuit and electronic device

An amplifier circuit for a microphone, comprising:

• a voltage regulator, having an output terminal;
• a first constant current source, having an input terminal connected to the output terminal of the voltage regulator;
• a first transistor, having a gate serving as an input terminal of the amplifier circuit, a source serving as an output terminal of the amplifier circuit, and a drain;
• a second transistor, having a source connected to an output terminal of the first constant current source, a gate connected to the source of the first transistor, and a drain connected to ground;
• a first driver, configured to achieve high power supply rejection ratio of the amplifier circuit and having a first end connected to the output terminal of the voltage regulator, a second end connected to the source of the second transistor, a third end connected to the source of the first transistor, a fourth end connected to the drain of the first transistor, and a fifth end connected to the ground;
• and
• a second driver, configured to achieve high acoustic overload point of the amplifier circuit and having a first end connected to a power supply, a second end connected to the output terminal of the voltage regulator, a third end connected to the source of the first transistor, a fourth end connected to the drain of the first transistor, and a fifth end connected to the ground;
• wherein a voltage output from the voltage regulator is lower than a voltage of the power supply.