FOLDED CASCODE OPERATIONAL AMPLIFIER WITH IMPROVED PHASE MARGINS THROUGH A FREQUENCY COMPENSATION

摘要

PURPOSE: A folded cascade operational amplifier is provided to obtain stable phase characteristic through same compensation capacitor by improving phase margins.;CONSTITUTION: A first folded cascode operational amplifier(510) of a first conductivity type comprises a first voltage line, a first node, a first current mirror serially connected between second nodes, a first bias circuit and a second bias circuit. A second folded cascode operational amplifier of a second conductivity type comprises a second voltage line, a third node, a second current mirror serially connected between fourth nodes, a third bias circuit and a fourth bias circuit. An output buffer(MP9, MN9) buffer an amplified voltage to an output terminal based on the voltage of the second node and the voltage of the fourth node.;COPYRIGHT KIPO 2010