An amplifier includes an input terminal for receiving an input signal, an output terminal for outputting an output signal, a first transistor, a second transistor having a first terminal coupled to a second terminal of the first transistor, a third transistor having a first terminal coupled to a second terminal of the second transistor, a capacitor coupled between a control terminal and a second terminal of the third transistor, a bias circuit coupled to the first terminal of the third transistor for providing a bias voltage to the third transistor, a fourth transistor having a first terminal coupled to the input terminal and a second terminal coupled to the output terminal for providing a bypass path, and a fifth transistor having a first terminal coupled to the first terminal of the first transistor and a second terminal coupled to the output terminal.