Programming instructions

JFETs (Junction FETs)

 National Instruments Corporation 4-19 Multisim Component Reference Guide

4.9.2 JFET Model Parameters and Defaults

= r

= 10% to 15% of the on-state drain-to-source resistance, R

DS(on)

Symbol Parameter Name Default Example Unit

VTO Threshold voltage -2 -2 V

BETA Transconductance

coefficient

0.0001 1e-03 A/V

LAMBDA Channel-length modulation 0 1e-04 1/V

RD Drain ohmic resistance 0 100 W

RS Source ohmic resistance 0 100 W

IS Gate-junction saturation

current

1e-14 1e-14 A

Cgd Zero-bias gate-drain junction

capacitance

0 1e-12 F

Cgs Zero-bias gate-source

junction capacitance

0 5e-12 F

PB Gate-junction potential 1 .06 V

B Doping tail parameter 1 1.1 -

KF Flicker noise coefficient 0 - -

AF Flicker noise exponent 1 - -

FC Coefficient for forward-bias

depletion capacitance

formula

.5 - -

TNOM Parameter measurement

temperature

27 50 °C

ComponentRef.book Page 19 Thursday, December 7, 2006 10:12 AM