An amplifier receives a differential signal and, in response, generates a first negative input current and a first positive input current. In a first operating mode, the amplifier receives a second differential signal, and, in response, generates a second negative input current and a second positive input current. In a second operating mode, the amplifier receives the second differential signal, and, in response, generates a third negative input current and a third positive input current. When the device is operating in the first operating mode, the first negative input current is summed with the second negative input current and the first positive input current is summed with the second positive input current. When the device is operating in the second operating mode, the first negative input current is summed with the third negative input current and the first positive input current is summed with the third positive input current.