Multistage amplifier with current limiting circuit

A multistage amplifier adapted to output a first output signal, comprising:

• an input stage circuit, comprising at least one amplifying circuit, wherein the amplifying circuit receives the first output signal and a reference signal, and accordingly generates a second output signal at an output terminal of the input stage circuit;
• a middle stage circuit, coupled to the input stage circuit, used to perform frequency compensation on the multistage amplifier;
• and
• an output stage circuit, coupled to the middle stage circuit and the input stage circuit, used to generate the first output signal at an output terminal of the output stage circuit according to the second output signal, wherein the output stage circuit comprises:
• at least one current limiting circuit, controlled by the second output signal to adjust a voltage level of the first output signal;
• and
• a power transistor, a control terminal of the power transistor being coupled to an output terminal of the middle stage circuit, a first terminal of the power transistor being coupled to a power supply, and a second terminal of the power transistor being coupled to the output terminal of the output stage circuit, wherein the power transistor is arranged to provide a current from the power supply to the output terminal of the output stage circuit the middle stage circuit further comprises a current mirror, which is arranged to mirror a reference current that is generated based on the second output signal, thereby to control the power transistor through the output terminal of the middle stage circuit.