Operational amplifier and pipeline AD converter

aaabbbaabbA differential voltage interconnect (W) electrically connects the gate electrode of a transistor to be used among differential transistors (T, T, . . . ) to an input node receiving an input voltage (Vinn), and a differential voltage interconnect (W) electrically connects the gate electrode of a transistor to be used among differential transistors (T, T, . . . ) to an input node receiving an input voltage (Vinp). A bias voltage interconnect (W) electrically connects the gate electrode of a transistor to be used among current source transistors (T, T, . . . ) to a bias node receiving a bias voltage (VBN), and a bias voltage interconnect (W) electrically connects the gate electrodes of transistors to be used among load transistors (T, T, . . . , T, T, . . . ) to a bias node receiving a bias voltage (VBP).