Semiconductor device

A semiconductor device comprising:

• a first terminal is connected with one end of a charging capacitor that generates a first power supply voltage;
• a second terminal that is connected with one end of a power supply wiring that supplies a second power supply voltage to a first circuit;
• a third terminal that is connected with one end of a smoothing capacitor that suppresses a fluctuation of the second power supply voltage;
• a first switch that is provided between the first terminal and the second terminal;
• a second switch that is provided between the second terminal and the third terminal;
• and
• a control circuit that controls an on/off state of the first switch and the second switch,
• wherein, after switching the first switch from the off state to the on state, the control circuit switches the second switch from the off state to the on state according to a voltage level of the second power supply voltage, and
• wherein the control circuit switches the first switch from the off state to the on state in response to that the first power supply voltage has reached a first setting voltage, and switches the first switch from the off state and the on state in response to that the first power supply voltage has reached a second setting voltage lower than the first setting voltage.