SAMPLED-DATA SIMULATION OF CIRCUITS WITH INTERNALLY CONTROLLED SWITCHES - Computer Methods for Analysis of Mixed-Mode Switching Circuits - page 177

Diodes belong to the category of voltage-controlled switches. The
constitutive equation of the diode is given by
1.2 MOSFETs
MOSFETs switches are controlled by the effective gate-source voltage
of the devices, as shown in Fig.8.2. The switching variable of a NMOS
switch is defined as
where is the threshold voltage of the NMOS switch. The constitu-
tive equation of the NMOS switch is given by
MOSFET switches also fall into the category of voltage-controlled
switches.