Patent ID: 6150884
Filing Date: 2000-11-21
Classification: H03F

Abstract:
A multistage operational amplifier circuit comprising:A. at least one input differential amplifier stage including a first differential amplifier pair, a first current mirror circuit, a first constant current source, the first differential amplifier pair having a first and a second output node, the first differential amplifier pair coupled between the first constant current source and the first current mirror circuit;B. a feed-forward amplifier stage having a second current mirror circuit and at least one feed-forward transistor having a gate, a drain and a source, the second current mirror circuit having a third and a fourth output node, the second current mirror circuit coupled to the drain of the at least one feed-forward transistor, the gate of the at least one feed-forward transistor coupled to the first output node; andC. an output amplifier stage having a second constant current source, at least one feedback element and a transistor having a gate, a drain and a source, the second constant current source and the drain of the transistor coupled to the fourth output node, the at least one feedback element coupled between the second output node and the fourth output node, the gate of the transistor coupled to the second output node.