Operational amplifier circuit

Abstract

The present invention provides an operational amplifier circuit which comprises an input circuit for outputting a difference between first and second input voltages, an amplifier circuit for amplifying the difference, a drive circuit for driving a latter stage in response to output from the amplifier circuit and an output circuit which constitutes the latter stage, wherein the amplifying circuit has a serial circuit composed of a first constant current source and a first transistor and a serial circuit composed of a second constant current source and a second transistor, the emitter of the first transistor is connected to the base of the second transistor, and the difference is applied to the base of the first transistor; the drive circuit has a serial circuit composed of third and fourth transistors whose collectors and emitters are interconnected and a third constant current source, the base and collector of the fourth transistor are interconnected, and the base of the third transistor is connected to the emitter of the second transistor; and the output circuit receives inputs from the collector of the second transistor and the base of the fourth transistor.

Dependencies are inferred from the claim text.