Model Parameter

Description

Unit

Default

LEVEL

1 selects the Basic SPICE JFET model

None

1 (default if LEVEL parameter is omitted)

ACM

Gate area calculation method

None

0

AF

Flicker noise exponent

None

1.0

ALIGN

Correction for gate misalignment

Meter

0.0

ALPHA (ALFA, ALPHA1)

Saturation factor

Volt^-1

2.0

AREA

Area factor

None

1.0

BETA

Transconductance (gain)

Amp/Volt²

1.0e-4

BEX

Temperature exponent to correct for low field mobility

None

0.0

CAPOP

Capacitor model selector

None

0

CAPDS (CDS)

Drain-source capacitance

Farad

0.0

CGD

Zero-bias gate-drain junction capacitance

ACM = 0 : Farad
ACM = 1 :
Farad/Meter²

0.0

CGS

Zero-bias gate-source junction capacitance

ACM = 0 : Farad
ACM = 1 :
Farad/Meter²

0.0

CRAT

Source ratio of gate capacitance

None

0.666

CTD

Temperature coefficient for gate-drain junction capacitance

°C^-1

0.0

CTS

Temperature coefficient for gate-drain junction capacitance

°C^-1

0.0

DCAP

Capacitance equation selector

None

2

EG

Energy gap for gate-drain and gate-source diodes at 0 °K.

electron-Volt

1.11

FC

Coefficient for PB in forward-bias capacitance calculations

None

0.5

GAMDS (GAMMA, GAMA)

Lowering coefficient for drain voltage-induced threshold voltage

None

0.0

GAP1

1st bandgap correction factor

electron-Volt/°K

7.02e-4

GAP2

2nd bandgap correction factor

°K

1108.0

GCAP

Zero-bias gate capacitance

ACM = 0 : Farad
ACM = 1 :
Farad/Meter²

Not used if not provided

GDSNOI

Channel noise coefficient (NLEV = 3)

None

1.0

HDIF

Distance of heavily-doped (low resistance) region from source or drain contact to lightly-doped region

Meter

0.0

IS

Gate junction saturation current.

ACM = 0: Amp
ACM = 1:
Amp/Meter²

1.0e-14

KF (KF4)

Flicker noise coefficient

None

0.0

L

FET gate length

Meter

0.0

LAMBDA (LAMB)

Channel length modulation factor

Volt^-1

0.0

LDEL

Difference between drawn length and actual or optical device length

Meter

0.0

LDIF

Distance of lightly-doped region from heavily-doped region to transistor edge

Meter

0.0

MJ

Grading coefficient for gate-drain and gate-source diodes

None

0.50

N

Emission coefficient for gate-drain and gate-source diodes

None

1.0

NG

Gate subthreshold factor

Volt^-1

0.0

NLEV

Noise equation selector

None

2

PB

Gate junction potential

Volt

0.8

RD

Drain ohmic resistance

Ohm

0.0

RG (RG2)

Gate ohmic resistance

Ohm

0.0

RS

Source ohmic resistance

Ohm

0.0

RSH

Sheet resistance of heavily-doped region

Ohm/square

0.0

RSHG

Gate sheet resistance

Ohm/square

0.0

RSHL

Sheet resistance of lightly-doped region

Ohm/square

0.0

TCV (VTOTC, AVT0)

Temperature compensation coefficient for threshold voltage VTO

°K^-1

0.0

TLEV

Temperature equation selector for junction diodes

None

0.0

TLEVC

Temperature equation selector for junction capacitances and potential

None

0.0

TNOM (TREF)

Nominal circuit temperature

°C

25.0

TPB

Temperature coefficient for gate junction potential PB

Volt/°K

0.0

TRD (TRD1, ARD)

Temperature coefficient for drain resistance RD

°K^-1

0.0

TRG (TRG1, ARG)

Temperature coefficient for gate resistance RG

°K^-1

0.0

TRS (TRS1, ARS)

Temperature coefficient for source resistance RS

°K^-1

0.0

TT

Transit time

Second

0.0

VTO (VT0, VPO)

Threshold voltage.

Volt

-2.0

W

FET gate width

Meter

0.0

WDEL

Difference between drawn width and actual or optical device width

Meter

0.0

XTI

Saturation current temperature exponent

None

3.0