| 摘要 |
PROBLEM TO BE SOLVED: To provide a switching power supply device capable of suppressing as much as possible power loss based on a step-down treatment at a time of normal output of a first power source voltage while making it possible to output stable power source voltage at a time of activating the first power source voltage.SOLUTION: At a time of activating a first power source voltage VB1, a first power source voltage generating circuit 23 outputs a voltage V1 to a power source input node N1. In a process in which a switching power source voltage of a main switching power source circuit is normally output by the first power source voltage VB1 being normally output, when an output voltage V2 of a second power source voltage generating circuit 24 reaches a predetermined voltage, the output voltage V2 is output to the power source input node N1.SELECTED DRAWING: Figure 2 |
