Patent ID: 6879212

Claim:
An operational amplifier comprising: a step-up circuit supplied with a first voltage, the step-up circuit providing a second voltage which is higher than the first voltage; a differential input circuit that provides a differential voltage signal, the differential input circuit including a first transistor having a first electrode supplied with the second voltage and a second electrode, a second transistor that receives a first input signal, the second transistor having a first electrode coupled to the second electrode of the first transistor and a second electrode, a third transistor that receives a second input signal, the third transistor having a first electrode coupled to the second electrode of the first transistor and a second electrode, a fourth transistor having a first electrode coupled to the second electrode of the second transistor and a second electrode supplied with a third voltage which is lower than the first voltage, and a fifth transistor having a first electrode coupled to the second electrode of the third transistor and a second electrode supplied with the third voltage; and an output circuit supplied with the first voltage, wherein the output circuit receives the differential voltage signal.