FET Calculator & Formula: drain current, transconductance

Field Effect Transistors (FETs) control current flow using an electric field rather than current injection, making them high input impedance devices suitable for low power and high frequency applications. Calculating FET parameters manually can be time consuming, especially when determining drain current, transconductance and operating regions. The FET Calculator enables quick evaluation of these parameters which helps users understand device behavior under different biasing conditions.

FET Calculator

EXAMPLE:

INPUTS:

• Idss = 10 mA
• Vp = -4 Volts
• Vgs = -2 V

OUTPUT:

• Drain Current (Id) = 2.5 mA
• JFET transconductance (gm) = 2.5 mS

FET Formula

Summary:

The FET calculator allows users to compute drain current, transconductance and bias region based on input voltages and device constants. This tool is valuable for electronics students and professionals working with analog and RF circuits.