Operational amplifier circuit

摘要

An operational amplifier circuit comprises a pair of emitter common transistors forming a differential amplifier circuit including a first conductivity type first and second transistors; a current mirror circuit including a second conductivity type third and fourth transistors having commonly connected bases and collectors which are connected with the first and second transistors, respectively and a second conductivity of fifth transistor having an emitter connected with the common bases and a base connected with the collector of the fourth transistor; and an output circuit including a second conductivity type sixth transistor having a base connected with the collector of the first transistor and a second conductivity type seventh transistor having a base connected with the emitter of the sixth transistor for outputting an output of the collector of the seventh transistor via a transistor buffer. The voltage between the collectors and the emitters of the first and second transistors of the emitter common transistor differential pair are equal to each other so that the current offset is reduced to improve the distortion factor characteristics.