Patent ID: 7310017
Filing Date: 2007-12-18
Classification: H03F

Abstract:
1. An operational amplifier circuit, comprising: a first differential transistor pair including first and second resistors that have a common source electrode connected with a first constant current source transistor, and a common node connected with a second constant current source transistor and serve as drain loads; and a second differential transistor pair including third and fourth resistors that have a common source electrode connected with a third constant current source transistor, and a common node connected with a fourth constant current source transistor and serve as drain loads, wherein the first differential transistor pair constitutes a signal input circuit of a gain path, and the second differential transistor pair constitutes a signal input circuit of a feedforward path for feedforward of the gain path to obtain a parallel path structure in which signals amplified through each of the paths are synthesized at an output end.