Device physicsMVP
Channel length / geometry explorer
How a transistor's width and length set the W/L ratio that scales its long-channel drive current.
Inputs
Result
Enter values and calculate to see the result.
Interpretation
Enter the channel width and length.
Formula
Id ∝ W / L
Long-channel drive current.
Variables
| Symbol | Variable | Unit |
|---|---|---|
| W | Channel width | m |
| L | Channel length | m |
| W/L | Aspect ratio driving current | dimensionless |
Assumptions & validity
This tool assumes:
- Educational long-channel model; drive current ∝ W/L.
- Ignores short-channel effects and velocity saturation (significant at small L).
Worked example
W = 1 µm, L = 0.1 µm.
W/L = 10 → ~10× the drive of a W/L = 1 device (long-channel)