JFET Model-Junction Field Effect Transistor Model

JFET_Model:Junction Field Effect Transistor Model

The SPICE J and Spectre jfet models are translated to the ADS JFET_Model. For translation information on the JFET device, refer to Jxxxxxxx for SPICE or JFET Device for Spectre.

For more information on the ADS model, place the model in a schematic and choose Edit > Component > Edit Component Parameters to view the model parameters. You can also click Help in the component editor dialog box for additional information.

Example SPICE Command Line:

.model Jmodel1 NJF Vto=-2.0

Example Spectre Command Line:

model jmod jfet beta=9e-5 lambda=0 type=n

SPICE and Spectre Dialect and Netlist Syntax:

Spice2/3:	.model mname NJF\|PJF [param= value]*
PSpice:	.model mname NJF\|PJF [param= value]*
HSpice:	.model mname NJF\|PJF LEVEL=1 [param= value]*
Spectre	model mname jfet type= [ n \| p ] ** [param= value]*

ADS Netlist Syntax:

model mname JFET NFET=[0|1] PFET=[0|1] [param= value]*

ADS Schematic Symbol:

Model Parameters:

For information on parameter format, refer to Using Parameter Mapping Tables to Understand a Translation.

JFET_Model Parameters
ADS	Default	Unit	Spice2/3	PSpice	HSpice	Spectre
NFET	yes					type n (NFET)
PFET	no					type n (NFET)
					Level=1
Vto	−2.0	V	x	x	x	vto -2.0 V
Beta	1e-4	A/V ²	x	x	x	beta 1e-4 A/V ²
Lambda	0.0	1/V	x	x	x	lambda 0.0 Ohms
Rd	0.0	ohms	x	x	x	rd 0.0 Ohms
Rs	0.0	ohms	x	x	x	rs 0.0 Ohms
Is	1e-14	A	x	x	x	is 1e-14 A
Cgs	0.0	F	x	x	x	cgs 0.0 F
Cgd	0.0	F	x	x	x	cgd 0.0 F
Pb	1.0	V	x	x	0.8 V	pb 1.0 V
Fc	0.5		x	x	x	fc 0.5
Tnom	25	°C	x	T_measured	-	tnom Set by defaults °C
						trise ^† 0.0 °C
Kf	0.0		x	x	x	kf 0.0
Af	1.0		x	x	x	af 1.0
Imax	1.6	A	-	-	-	imax 1.0 A
N	1.0		-	x	x	n 1.0
Isr	0.0	A	-	x	-	-
Nr	2.0		-	x	-	-
Alpha	0.0	1/V	-	x	-	ai 0.0 1/V
Vk	0.0	V	-	x	-	bi 0.0 V
M	0.5		-	x	MJ	-
Vtotc	0.0	V/°C	-	x	TVC	tcv 0.0 1/°C
Betatce	0.0	%/°C	-	x	-	-
Xti	3.0		-	x	0.0	-
wBvgs	infinity	V				bvj infinity V
wBvgd	infinity	V				bvj infinity V
*^† See Temp* instance parameter**