Functional Region of MOSFET
The full form of MOSFET is Metal Oxide Semiconductor Field Effect Transistor. If a MOSFET's gate and drain are shorted, it can function as a small-signal resistor. When the Drain, Source, and bulk (body) of a MOSFET are shorted, this acts as one capacitor plate, and the Gate acts as another capacitor plate. The three main functional regions of a MOSFET are as follows:
- Cut-off Region: The MOSFET is regarded as being in its "OFF" state when it is in the cut-off region. This means that no current passes through it when it is turned OFF.
- Saturation Region: Saturation is the state where the MOSFET's current flow is constant. It acts as a closed switch in this area, enabling current to flow freely.
- Linear/Ohmic Region: Increasing the voltage across the drain and source also increases the current flowing through the MOSFET in the linear/ohmic zone.
The MOSFET is considered the basic building block and the most frequently manufactured device. It is also the most common semiconductor device in both analogue and digital circuits.