MOSFET model

The Multisim MOSFET model is based on the Shichman-Hodges SPICE3 MOSFET model.

See below for details. 

Large signal model

In the following sections, all transistor node voltage references are with respect to the internal nodes (that is, the ohmic resistance pin that is connect the inside of the structure.) 

Static model 

Drain-source current: 

The forward current is the sum of the normal and recombination currents: 

Substrate currents: 

Capacitances 

Gate capacitances: 

Junction capacitances: 

Temperature dependent parameters 

The following parameters are functions of temperature. T is the operating temperate and TNOM is the nominal (or measured temperature). T and TNOM can be adjusted in a number of ways. 

Noise model 

The MOSFET has six noise generators; four thermal noise generators associated with the four ohmic resistances, a shot noise generator and a flicker noise generator associated with the channel. 

Ohmic resistance noise: 

Shot noise:

Flicker noise:

References 

1. G. Massobrio and P. Antognetti, Semiconductor Device Modeling with SPICE, 2nd edition, McGraw-Hill, 1993. 
   
2. A. Vladimirescu, The SPICE Book, Wiley, 1994.