A fully-differential amplifier circuit comprises a differential amplifier configured to differentially amplify first and second input signals serving as an input differential pair to generate a pair of first and second intermediate signals, first and second class AB amplifiers configured to amplify the first and second intermediate signals to generate first and second output signals, wherein the first and second output signals serve as an output differential pair, the first class AB amplifier amplifies the first intermediate signal with reference to a reference voltage adjusted by a first feedback signal that is a common mode component of the first output signal and the second output signal, and the second class AB amplifier amplifies the second intermediate signal with reference to a reference voltage adjusted by a second feedback signal that is a common mode component of the first output signal and the second output signal.