Editing MOSFET (section)

==== Single-type ====
This analog switch uses a four-terminal simple MOSFET of either P or N type.

In the case of an n-type switch, the body is connected to the most negative supply (usually GND) and the gate is used as the switch control. Whenever the gate voltage exceeds the source voltage by at least a threshold voltage, the MOSFET conducts. The higher the voltage, the more the MOSFET can conduct. An N-MOS switch passes all voltages less than ''V''{{sub|gate}} − ''V''{{sub|tn}}. When the switch is conducting, it typically operates in the linear (or ohmic) mode of operation, since the source and drain voltages will typically be nearly equal.

In the case of a P-MOS, the body is connected to the most positive voltage, and the gate is brought to a lower potential to turn the switch on. The P-MOS switch passes all voltages higher than ''V''{{sub|gate}} − ''V''{{sub|tp}} (threshold voltage ''V''{{sub|tp}} is negative in the case of enhancement-mode P-MOS).