A FBDDA amplifier comprising: a first differential input stage, which receives an input voltage; a second differential input stage, which receives a common-mode voltage; a first resistive-degeneration group coupled to the first differential input; a second resistive-degeneration group coupled to the second differential input; a differential output stage, generating an output voltage; a first switch coupled in parallel to the first resistive-degeneration group; and a second switch coupled in parallel to the second resistive-degeneration group. The first and second switches are driven into the closed state when the voltage input assumes a first value such that said first input stage operates in the linear region, and are driven into the open state when the voltage input assumes a second value, higher than the first value, such that the first input stage operates in a non-linear region.