Patent ID: 6696895
Filing Date: 2004-02-24
Classification: H03F

Abstract:
A push-pull amplifier comprising:a source follower circuit that receives an input signal at its gate, and outputs an input current that corresponds to said input signal; a current transfer circuit that receives said input current and maintains constant the sum of said input current and an output current that is to be applied to a first node; and a push-pull circuit including a first transistor that directly receives said input signal at its gate, and a second transistor having its gate connected to said first node, wherein said current transfer circuit includes a first current mirror circuit including a first input transistor whose drain and gate are supplied with said input current, and a first output transistor that has its drain connected to a second node and that generates a first output current with the same value as said input current, a second current mirror circuit including a second input transistor that has its drain and gate connected to said second node and that generates a second input current, and a second output transistor that has its drain connected to said first node and that supplies said first node with said output current with the same value as said second input current, and a constant-current source supplying a constant current to said second node.