2
If the inductor current increases and the total of the current signal IL and the ramp signal becomes larger than the control signal 1cm], the latch circuit 5 is reset. When the latch circuit 5 is in a reset state, the sWitches S1 and S2 are respectively held OFF and ON. In this state, the inductor current ?oWs via the sWitch S2, and decreases With time. Thereafter, When the rising edge of the pulse signal from the oscillator 2 is input to the latch circuit 5, the latch circuit 5 is again set and the above described process is repeated.