Patent ID: 8330543
Filing Date: 2012-12-11
Classification: H03F

Abstract:
1. A differential amplifier, electrically coupled between a first voltage and a second voltage, comprising: a pair of input transistors, for providing a pair of input terminals; a pair of load transistors, for providing a pair of output terminals, having a pair of first terminals electrically coupled to the first voltage; a pair of impedance devices, electrically coupled between the pair of output terminals in series; a pair of auxiliary input transistors, having a pair of control terminals, a pair of first terminals, and a pair of second terminals, wherein the pair of control terminals are respectively electrically coupled to the pair of input terminals, wherein the pair of input transistors and the pair of auxiliary input transistors have reverse conductive type; and a pair of shield transistors, having a pair of control terminals, a pair of first terminals, and a pair of second terminals, wherein the pair of first terminals are respectively electrically coupled to the pair of second terminals of the pair of auxiliary input transistors and are coupled to the second voltage through a pair of current sources, wherein the pair of second terminals are respectively electrically coupled to the pair of output terminals, wherein the pair of impedance devices has a connection node between the pair of output terminals, the connection node is also connected to gate electrodes of the pair of auxiliary input transistors or gate electrodes of the pair of shield transistors.