Switch circuit device, and wireless circuit device and sampling circuit device employing the same

A switch circuit comprising:

• a plurality of p-ch MOSFETs whose gates are connected together and whose drains and sources are connected in series;
• an n-ch MOSFET whose gate is connected to the gates of the plurality of p-ch MOSFETs and whose source is connected to the source and drain connected to each other of at least one pair of adjacent p-ch MOSFETs of the plurality of p-ch MOSFETs;
• an inverter for inverting and outputting a control voltage;
• and
• a voltage changing circuit for applying a high voltage to the drain of the n-ch MOSFET while a low-level control voltage inverted and output by the inverter is applied to the gate of the n-ch MOSFET, the high voltage being higher than the low-level control voltage, and a low voltage to the drain of the n-ch MOSFET while a high-level control voltage inverted and output by the inverter is applied to the gate of the n-ch MOSFET, the low voltage being lower than the high-level control voltage.