an operational amplifier circuit includes a differential operational amplifier and a common mode feedback circuit with first and second transistors having source electrodes connected to first and second supply voltage conductors and drains coupled to first and second outputs of the operational amplifier , respectively . first and second capacitors are connected in series between gate electrodes of the first and second transistors and have a common point connected to the first output . a first switch capacitor circuit periodically refreshes the first capacitor to a voltage equal to the average of the first and second supply conductor voltages minus first and second predetermined bias voltages , respectively . a second similar common mode feedback circuit is coupled to the second output a differential output voltage produced by the operational amplifier results in equal excursions of the first and second outputs on opposite sides of the common mode feedback signal .