drainjännitteestä

Drainjännitteestä, also known as drain voltage, refers to the electrical potential difference between the drain terminal and the source terminal of a field-effect transistor (FET). In an N-channel enhancement-mode MOSFET, for example, drain voltage is the voltage applied to the drain relative to the source. This voltage, along with the gate-source voltage, controls the flow of current through the channel between the source and the drain. As the drain voltage increases, the electric field at the drain end of the channel becomes stronger, influencing the charge carriers.

The behavior of the drain current is significantly dependent on the drain-source voltage (Vds) and the gate-source voltage (Vgs). In the ohmic or linear region, the drain current increases almost linearly with drain voltage for a constant gate voltage. However, as the drain voltage is increased further, a point is reached where the drain current saturates and becomes largely independent of further increases in drain voltage. This operating region is known as the saturation region and is crucial for amplifier applications. The magnitude of the drain voltage is a key parameter in determining the operating point and performance characteristics of a FET.