Patent ID: 7193401
Filing Date: 2007-03-20
Classification: H02M,Y02B

Abstract:
1. A control circuit of a current mode control type DC—DC converter that controls a main switching transistor in accordance with a clock signal, comprising: a timing adjustment circuit that outputs a timing signal for determining a timing for shifting the main switching transistor from a second state to a first state; and a phase comparator that detects a phase difference between the timing signal and the clock signal to output a phase difference signal to the timing adjustment circuit in accordance with the phase difference, wherein the timing adjustment circuit prolongs a delay time after the main switching transistor shifts from the first state to the second state until the timing adjustment circuit outputs the timing signal in accordance with an advance amount of a phase when the phase of the timing signal is more advanced than a phase of the clock signal, and the timing adjustment circuit shortens the delay time in accordance with a delay amount of a phase when the phase of the timing signal is delayed behind a phase of the clock signal.