Patent ID: 7268448
Filing Date: 2007-09-11
Classification: H02M

Abstract:
1. A DC-DC converter control circuit comprising: a first comparator that compares an output voltage and a first reference voltage and that detects a case where the output voltage crosses the first reference voltage to output a detection signal; a flip-flop that controls a main switching transistor and that according to the output signal transits from a first state to a second state; a phase comparator that detects the phase difference between a phase reference signal input from outside and the detection signal and outputs a phase difference signal corresponding to the phase difference; and, a delay circuit that is connected between an output and input of the flip-flop circuit and to which there is input the phase difference signal, whereby the delay circuit, in a case where the phase of the detection signal is more advanced than the phase of the phase reference signal, after having imparted an amount of retardation time that has been increased correspondingly to the amount of phase advanced to a transition signal input from the flip-flop at the time of the flip-flop's transiting from the first state to the second state, outputs the transition signal to which the amount of the retardation time is imparted, to the flip-flop; and the delay circuit, in a case where the phase of the detection signal is more retarded than the phase of the phase reference signal, after having imparted the amount of retardation time decreased correspondingly to the amount of phase retarded to the transition signal, outputs the transition signal to which the amount of the retardation time is imparted, to the flip-flop, whereby the flip-flop, correspondingly to that the transition signal to which the amount of retardation time has been imparted is input, transits from the second state to the first state.