Patent ID: 8749275

Claim:
A differential circuit comprising: a first input part to which a first input voltage is input; a second input part to which a second input voltage is input; a reference voltage input part to which a reference voltage is input, the reference voltage input part being common to form differential pairs by pairing with respective ones of the first input part and the second input part; a current source that drives the differential pairs; a current mirror that generates a first output current and a second output current, according to a current that flows through the reference voltage input part according to at least one voltage difference of a first voltage difference between the first input voltage and the reference voltage and a second voltage difference between the second input voltage and the reference voltage; a first output part that outputs a signal according to the first voltage difference, according to a current that flows through the first input part according to the first voltage difference and the first output current; and a second output part that outputs a signal according to the second voltage difference, according to a current that flows through the second input part according to the second voltage difference and the second output current, wherein the differential circuit is used as operational amplifier that increases output impedances of plural cascode circuits of an output stage of an operational amplifier circuit.