nmosfet :
An n-type MOSFET transistor.

The nmosfet primitive represents a four-terminal n-channel MOSFET.

The current version implements an approximate EKV transistor model, consisting of two transconductance stages with rectified linear characteristics:

Id1 = KP * W/L * (Vgs - Vth)    if Vgs > Vth
Id2 = KP * W/L * (Vgd - Vth)    if Vgd > Vth
Ids = Id1 - Id2

Each capacitance parameter (Cgs, Cgd, Cgb, Csb, Cdb) is an array of three real-typed values each expressing the capacitance between the corresponding terminals of the transistor operating in cut-off, linear, and saturation region, respectively.

This primitive is a pseudo-module to describe a structural netlist of electrical circuits and not a behavioral model by itself. The XMODEL simulator extracts an event-driven behavioral model at run-time based on the circuit network described by these circuit-level pseudo-modules.

Input/Output Terminals

Name	I/O	Type	Description
d	input	xreal	drain
g	input	xreal	gate
s	input	xreal	source
b	input	xreal	bulk

Parameters

Name	Type	Default	Unit	Description
W	real	1e-6	m	channel width
L	real	1e-6	m	channel length
Kp	real	1e-3	A/V	intrinsic transconductance
Kp_data	real	‘{0.0}	A/V	intrinsic transconductance data
Vth	real	0.0	V	threshold voltage
Ro	real	`INFINITY	V	output resistance
Cgs	real_array	‘{0.0,0.0,0.0}	farad/m	G-to-S capacitance per width (off,lin,sat)
Cgd	real_array	‘{0.0,0.0,0.0}	farad/m	G-to-D capacitance per width (off,lin,sat)
Cgb	real_array	‘{0.0,0.0,0.0}	farad/m	G-to-B capacitance per width (off,lin,sat)
Csb	real_array	‘{0.0,0.0,0.0}	farad/m	S-to-B capacitance per width (off,lin,sat)
Cdb	real_array	‘{0.0,0.0,0.0}	farad/m	D-to-B capacitance per width (off,lin,sat)