Patent ID: 6987420

Claim:
An operational amplifier comprising: a first differential transistor pair which is disposed between a first power supply conductor and a second power supply conductor, and which receives differential input signals at a first differential input terminal and a second differential input terminal thereof; a second differential transistor pair which is disposed between the first power supply conductor and the second power supply conductor, and which receives the differential input signals at a third differential input terminal and a fourth differential input terminal thereof; a first current source circuit coupled between the first differential transistor pair and the second power supply conductor; a second current source circuit coupled between the second differential transistor pair and the first power supply conductor; an output terminal for outputting an output signal; a first transistor for sourcing a drive output current via the output terminal; a second transistor for sinking a drive output current via the output terminal; an output driver stage circuit for controlling the drive output current corresponding to a signal output potential level of the output signal; a first phase inverter circuit which responds to a drive output potential level of the output driver stage circuit and which controls a circuit current of the first differential transistor pair in response to the rise or fall of the signal output potential level; and a second phase inverter circuit which responds to the drive output potential level of the output driver stage circuit and which controls a circuit current of the second differential transistor pair in response to the rise or fall of the signal output potential level.