a latch circuit Which is set by a signal of a predetermined cycle and is reset by the reset signal;
a driving circuit Which drives the sWitch based on a state held by said latch circuit;
a capacitor Which stores an electric charge Which is used When said driving circuit holds the sWitch ON; and
a correcting circuit Which generates a correcting signal Which rises With time While said latch circuit is in a set state, and for correcting the signal corresponding to the
inductor current With the correcting signal.