An embodiment circuit includes an operational amplifier having a first output terminal and a second output terminal. The circuit further includes a detector coupled between the first output terminal and the second output terminal of the operational amplifier. The detector is configured to detect a common-mode output voltage at the first output terminal and the second output terminal of the operational amplifier. The circuit also includes a feedback amplifier having a first input terminal coupled to the detector and a second input terminal configured to receive a reference voltage. The feedback amplifier is configured to generate a feedback signal based on the common-mode output voltage and the reference voltage and to provide the feedback signal to the operational amplifier. The circuit additionally includes an impedance element having a first terminal coupled to the first input terminal of the feedback amplifier and a second terminal coupled to a supply voltage.