A differential amplifying unit includes a first input transistor and a second input transistor forming a differential pair, and a first tail current source and a second tail current source. An output stage includes a first output transistor and a second output transistor that can be driven by an output of the differential amplifying unit. A controller performs control such that during startup, a load is driven by the first tail current source and the first output transistor, and such that after startup, the load is driven by the first tail current source, the second tail current source, the first output transistor, and the second output transistor.