Patent ID: 6583669
Filing Date: 2003-06-24
Classification: H03F

Abstract:
A class AB amplifier that operates from a high power supply and a low power supply, comprising:a first transistor having a gate terminal that is coupled to a first node, a source terminal that is coupled to the low power supply, and a drain terminal that is coupled a second node; a second transistor having a gate terminal that is coupled to the first node, a source terminal that is coupled to the low power supply, and a drain terminal that is coupled to a third node; a third transistor having a gate terminal that is coupled to a fourth node, a source terminal that is coupled to the second node, and a drain terminal that is coupled to a fifth node; a fourth transistor having a gate terminal that is coupled to the fourth node, a source terminal that is coupled to the third node, and a drain terminal that is coupled to the first node; a fifth transistor having a gate terminal that is coupled to a sixth node, a source terminal that is coupled to the second node, and a drain terminal that is coupled to the sixth node; a sixth transistor having a gate terminal that is coupled to the sixth node, a source terminal that is coupled to the third node, and a drain terminal that is coupled to a seventh node; a seventh transistor having a gate terminal that is coupled to an eighth node, a source terminal that is coupled to the high power supply, and a drain terminal that is coupled to a ninth node; an eighth transistor having a gate terminal that is coupled to the eighth node, a source terminal that is coupled to the high power supply, and a drain terminal that is coupled to a tenth node; a ninth transistor having a gate terminal that is coupled to an eleventh node, a source terminal that is coupled to the ninth node, and a drain terminal that is coupled to the sixth node; a tenth transistor having a gate terminal that is coupled to the eleventh node, a source terminal that is coupled to the tenth node, and a drain terminal that is coupled to the eighth node; an eleventh transistor having a gate terminal that is coupled to the fifth node, a source terminal that is coupled to the ninth node, and a drain terminal that is coupled to the fifth node; a twelfth transistor having a gate terminal that is coupled to the fifth node, a source terminal that is coupled to the tenth node, and a drain terminal that is coupled to a twelfth node; a floating current source that is coupled between the first node and the eighth node; and a resistive circuit that is coupled between the seventh node and the twelfth node, wherein the second and third nodes are arranged to operate as inputs to a class AB turn-around stage, and the seventh and twelfth nodes operate as drive points for an output of the class AB turn-around stage.