AExE01 · Chapter 1Basic Electrical & Electronics🏛️ Past Licensure QuestionID: 8a00bdb3
What is the drain current equation for an enhancement-mode MOSFET operating in saturation (neglecting channel-length modulation)?
What is the drain current equation for an enhancement-mode MOSFET operating in saturation (neglecting channel-length modulation)?
Multiple Choice Options
- A✓ Correct Option
Id = (1/2) un Cox (W/L) (VGS - VTH)^2
- B
Id = K VDS (VGS - VTH) - (1/2) K VDS^2
- C
Id = VGS / RDS
- D
Id = B (VGS - VTH) VDS
Detailed Technical Solution & Explanation
In an enhancement-mode NMOS transistor operating in the saturation region (), the channel pinches off at the drain end. The resulting saturation drain current follows the square-law equation: .
Option Analysis:
•
Option A (un Cox (W/L) (VGS - VTH)^2): ** Correct. Standard Shockley square-law formulation for saturation mode.
•
Option B (- (1/2) K VDS^2): ** Incorrect. Represents triode (linear) region conduction.
•
Option C (Id = VGS / RDS): Incorrect. Ohm's law representation for deep linear region.
•
Option D (VDS): ** Incorrect.
Reference: Demo2 · Set 1NEC Licensure Syllabus