| 摘要 |
<P>PROBLEM TO BE SOLVED: To achieve a soft start in a digital power-supply device including a delta-sigma modulation circuit. <P>SOLUTION: A digital power-supply device comprises a switching regulator unit having a switching element, a signal processing circuit generating a signal to be modulated on the basis of an output voltage of the switching regulator unit, and a delta-sigma modulation circuit modulating the signal to be modulated and outputting the signal as a switching control signal controlling the switching element. The delta-sigma modulation circuit includes a feedback path that feeds back the switching control signal and a memory element that stores the feedback coefficient for determining the feedback factor of the feedback signal, and modulates the signal to be modulated using the feedback signal from the feedback path and the feedback coefficient stored in the memory element. The signal processing circuit includes a feedback-coefficient change circuit that gradually changes the value of the feedback coefficient to be stored in the memory element from the allowable maximum value to the setting value while a predetermined time passes after the start. <P>COPYRIGHT: (C)2013,JPO&INPIT |
