Power Source Connection Circuit

A power source connection circuit comprising:

• a MOS switch having a drain connected to an input terminal and a source connected to an output terminal;
• a step-up circuit for supplying electric charges to a gate of the MOS switch;
• an electric-charge discharging unit coupled between the gate and a ground terminal;
• and
• a comparator for comparing a voltage of the output terminal with a reference voltage,
• wherein the electric-charge discharging unit includes:
• a switch coupled between the gate and the ground terminal;
• and
• a clock signal providing unit for providing a clock signal to a control terminal of the switch according to an output signal of the comparator.

A power source connection circuit comprising:

• a MOS switch for receiving an input voltage from a first terminal and outputting an output voltage to a second terminal;
• a step-up circuit for supplying electric charges to a gate of the MOS switch;
• and
• an electric-charge discharging unit for forming a current path from the gate to a third terminal when the output voltage is lower than a reference voltage, and interrupting the current path when the output voltage is higher than the reference voltage.