An E-MOSFET has values of VGSth) = 4 V and IDon) = 12 mA @ VGS = 10 V. The device is being used in a circuit that has a value of VGS = 6 V. What is the value of ID for the circuit?

Question

Quizplus · Accepted Answer

The E-MOSFET operates in the saturation region when $V_{GS} > V_{GS(th)}$. The drain current ($I_D$) can be calculated using the square law model: $I_D = I_{Don} \left(\frac{V_{GS} - V_{GS(th)}}{V_{GS(on)} - V_{GS(th)}}\right)^2$, where $I_{Don}$ is the drain current at $V_{GS(on)}$, $V_{GS}$ is the gate-source voltage, and $V_{GS(th)}$ is the threshold voltage. Substituting the given values: $I_D = 12mA \left(\frac{6V - 4V}{10V - 4V}\right)^2 = 12mA \left(\frac{2}{6}\right)^2 = 12mA \times \frac{1}{9} = 1.33mA$.

An E-MOSFET Has Values of VGSth) = 4 V and IDon)