Patent ID: 7474152

Claim:
An operational amplifier circuit for generating an output signal from a first input signal and a second input signal, the operational amplifier circuit comprising: a differential input circuit including: a first transistor for receiving the first input signal and generating a first voltage; and a second transistor for receiving the output signal as the second input signal and generating a second voltage; an output stage circuit connected to the differential input circuit and including: a third transistor responsive to the second voltage; a fourth transistor operatively connected to the third transistor, with a first node being formed between the third transistor and the fourth transistor; a fifth transistor responsive to the first voltage; and a sixth transistor connected in series to the fifth transistor, with the fourth transistor and the sixth transistor forming a first current mirror, a second node being formed between the fifth transistor and the sixth transistor, and the output signal being generated at the second node; and a control circuit, connected to the differential input circuit and the output stage circuit, for controlling the potential at the first node using the first input signal.