Comparison of MOSFET models

Contents - Glossary - Study Aids - MOSFET models

A comparison of a numeric solution helps to understand the difference between the models as well as their range of applicability. Click on the underlined text to load the corresponding EXCEL sheet.

Comparison of current-voltage characteristics: Both models yield similar current-voltage characteristics. The quadratic model predicts a larger drain current. The difference is more pronounced for MOSFETs with a higher substrate doping and a thicker gate oxide.

Comparison of the square root of the drain current versus the gate voltage : A straight line on this plot represents a quadratic dependence between the drain current and the gate voltage. While it is no surprise that the quadratic model yields a straight line, one finds that the variable depletion charge model also yields a straight line so that it can be accurately approximated using the quadratic model with a modified K value.