Patent ID: 7652538

Claim:
An operational amplifier, comprising: a first supply voltage rail; a second supply voltage rail; a differential amplifier input stage comprising a first signal input terminal and a second signal input terminal; a folded cascode stage connected to an output of the differential amplifier input stage, the folded cascode stage comprising first, second, third and fourth nodes; an output driver stage for generating a driving current to an output node of the operational amplifier, the output driver stage comprising first and second output transistors connected to the first and second nodes, respectively, of the folded cascode stage; and a compensation circuit connected to the third and fourth nodes of the folded cascode stage and to the output node of the operational amplifier, wherein the output node is connected to the second signal input terminal of the differential amplifier input stage, wherein the compensation circuit comprises: a first and second capacitor; and a first, second, third and fourth switch; wherein the first switch and the first capacitor are serially connected between the first supply voltage rail and the output node, wherein the second switch and the second capacitor are serially connected between the second supply voltage rail and the output node; wherein the third switch is connected to the third node of the folded cascode stage and to a node between the first switch and the first capacitor; and wherein the fourth switch is connected to the fourth node of the folded cascode stage and to a node between the second switch and the second capacitor.