Patent ID: 7394671
Filing Date: 2008-07-01
Classification: H02M,H05B,Y02B

Abstract:
1. A controller IC for controlling a first semiconductor switch and a second semiconductor switch for driving a load, comprising: an oscillator block for generating a first triangular wave signal and a second triangular wave signal having a relation in which said first triangular wave signal is reversed when a capacitor for frequency decision and a resistor for frequency decision are connected, a pulse width modulation circuit for comparing the first triangular wave signal with a feedback signal formed based on a current flowing through the load and generating a first pulse width modulation signal and comparing the second triangular wave signal with the feedback signal and generating a second pulse width modulation signal, and a driving signal output block for alternately outputting a first switch driving signal for turning on the first semiconductor switch based on the first pulse width modulation signal and a second switch driving signal for turning on the second semiconductor switch based on the second pulse width modulation signal, characterized in that the driving signal output block generates the first switch driving signal and the second switch driving signal at timing at which an off period during which both of the first semiconductor switch and the second semiconductor switch are turned off is set between a period for which the first semiconductor switch is in the on state and a period for which the second semiconductor switch is in the on state.