Metal Oxide Semiconductor Field-Effect Transistor (MOSFET) Model

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Model Kind

Transistor

Model Sub-Kind

MOSFET

SPICE Prefix

M

SPICE Netlist Template Format

@DESIGNATOR %1 %2 %3 %3 @MODEL ?LENGTH|L=@LENGTH| ?WIDTH|W=@WIDTH| ?"DRAIN AREA"|AD=@"DRAIN AREA"| ?"SOURCE AREA"|AS=@"SOURCE AREA"| ?"DRAIN PERIMETER"|PD=@"DRAIN PERIMETER"| ?"SOURCE PERIMETER"|PS=@"SOURCE PERIMETER"| ?NRD|NRD=@NRD| ?NRS|NRS=@NRS| &"STARTING CONDITION" ?"INITIAL D-S VOLTAGE"|IC=@"INITIAL D-S VOLTAGE", @"INITIAL G-S VOLTAGE", @"INITIAL B-S VOLTAGE"| ?TEMPERATURE|TEMP=@TEMPERATURE|

Parameters (definable at component level)

The following component-level parameters are definable for this model type and are listed on the Parameters tab of the Sim Model dialog. To access this dialog, simply double-click on the entry for the simulation model link in the Models region of the Component Properties dialog.

Length

channel length (in meters).

Width

channel width (in meters).

Drain Area

area of the Drain diffusion (in sq.meters).

Source Area

area of the Source diffusion (in sq.meters).

Drain Perimeter

perimeter of drain junction (in meters). (Default = 0).

Source Perimeter

perimeter of source junction (in meters). (Default = 0).

NRD

equivalent number of squares of the drain diffusion (Default = 1).

NRS

equivalent number of squares of the source diffusion (Default = 1).

Starting Condition

set to OFF to set terminal voltages to zero during operating point analysis. Can be useful as an aid in convergence.

Initial D-S Voltage

time-zero voltage across Drain-Source terminals (in Volts).

Initial G-S Voltage

time-zero voltage across Gate-Source terminals (in Volts).

Initial B-S Voltage

time-zero voltage across Bulk (substrate)-Source terminals (in Volts).

Temperature

temperature at which the device is to operate (in Degrees Celsius). If no value is specified, the default value assigned to TEMP on the SPICE Options page of the Analyses Setup dialog will be used (Default = 27).

M

multiplication factor. (Default = 1). This parameter is only available when using the EKV model.

Parameters (definable within model file)

The following is a list of parameters that can be stored in the associated model file, when using the Shichman-Hodges, MOS2, MOS3 or MOS6 models:

LEVEL

model index (Default = 1).

VTO

zero-bias threshold voltage V TO (in Volts). (Default = 0).

KP

transconductance parameter (in A/V 2 ). (Default = 2.0e-5).

GAMMA

bulk threshold parameter γ (in V 1/2 ). (Default = 0).

PHI

surface potential φ (in Volts). (Default = 0.6).

LAMBDA

channel length modulation λ (in 1/V). This parameter is applicable to MOS1 and MOS2 model types only. (Default = 0).

RD

drain ohmic resistance (in Ohms). (Default = 0).

RS

source ohmic resistance (in Ohms). (Default = 0).

CBD

zero-bias B-D junction capacitance (in Farads). (Default = 0).

CBS

zero-bias B-S junction capacitance (in Farads). (Default = 0).

IS

bulk junction saturation current I S (in Amps). (Default = 1.0e-14).

PB

bulk junction potential (in Volts). (Default = 0.8).

CGSO

Gate-Source overlap capacitance per meter channel width (in Farads per meter). (Default = 0).

CGDO

Gate-Drain overlap capacitance per meter channel width (in Farads per meter). (Default = 0).

CGBO

Gate-Bulk overlap capacitance per meter channel length (in Farads per meter). (Default = 0).

RSH

Drain and Source diffusion sheet resistance (in Ohms). (Default = 0).

CJ

zero-bias bulk junction bottom capacitance per square meter of junction area (in Farads/m 2 ). (Default = 0).

MJ

bulk junction bottom grading coefficient (Default = 0.5).

CJSW

zero-bias bulk junction sidewall capacitance per meter of junction perimeter (in Farads/meter). (Default = 0).

MJSW

bulk junction sidewall grading coefficient (Default = 0.5 
- LEVEL1; 0.33 
- LEVEL2,3).

JS

bulk junction saturation current per square meter of junction area (in Amps/m 2 ).

TOX

oxide thickness (in meters). (Default = 1.0e-7).

NSUB

substrate doping (in 1/cm 3 ). (Default = 0).

NSS

surface state density (in 1/cm 2 ). (Default = 0).

NFS

fast surface state density (in 1/cm 2 ). (Default = 0).

TPG

type of gate material:
+1 (default) = opposite to substrate
-1 = same as substrate
0 = Al gate

XJ

metallurgical junction depth (in meters). (Default = 0). This applies to Levels 2 (MOS2) and 3 (MOS3) only.

LD

lateral diffusion (in meters). (Default = 0).

UO

surface mobility (in cm 2 /Vs). (Default = 600).

UCRIT

critical field for mobility degradation (in V/cm). This parameter is applicable to the MOS2 model only. (Default = 1.0e4).

UEXP

critical field exponent in mobility degradation. This parameter is applicable to the MOS2 model only. (Default = 0).

UTRA

transverse field coefficient (mobility). This parameter has been deleted with respect to the MOS2 model. (Default = 0).

VMAX

maximum drift velocity of carriers (in m/s). (Default = 0).

NEFF

total channel-charge (fixed and mobile) coefficient. This parameter is applicable to the MOS2 model only. (Default = 1).

KF

flicker noise coefficient (Default = 0).

AF

flicker noise exponent (Default = 1).

FC

coefficient for forward-bias depletion capacitance formula (Default = 0.5).

DELTA

width effect on threshold voltage. This parameter is applicable to MOS2 and MOS3 model types only. (Default = 0).

THETA

mobility modulation (in 1/V). This parameter is applicable to the MOS3 model only. (Default = 0).

ETA

static feedback. This parameter is applicable to the MOS3 model only. (Default = 0).

KAPPA

saturation field factor. This parameter is applicable to the MOS3 model only. (Default = 0.2).

TNOM

parameter measurement temperature (in °C) 
- If no value is specified, the default value assigned to TNOM on the SPICE Options page of the Analyses Setup dialog will be used (Default = 27).

The following is a list of parameters that can be stored in the associated model file, when using the BSIM or BSIM2 models:

LEVEL

model index (Default = 1).

VFB*

flat-band voltage (in Volts).

PHI*

surface inversion potential (in Volts).

K1*

body effect coefficient (in V 1/2 ).

K2*

Drain/Source depletion charge-sharing coefficient.

ETA*

zero-bias drain-induced barrier-lowering coefficient.

MUZ

zero-bias mobility (in cm 2 /Vs).

DL

shortening of channel (in μm).

DW

narrowing of channel (in μm).

U0*

zero-bias transverse-field mobility degradation coefficient (in V -1 ).

U1*

zer0-bias velocity saturation coefficient (in μm/V).

X2MZ*

sens. of mobility to substrate bias at V ds =0 (in cm 2 /V 2 s).

X2E*

sens. of drain-induced barrier lowering effect to substrate bias (in V -1 ).

X3E*

sens. of drain-induced barrier lowering effect to drain bias at V ds =V dd (in V -1 ).

X2U0*

sens. of transverse field mobility degradation effect to substrate bias (in V -2 ).

X2U1*

sens. of velocity saturation effect to substrate bias (in μmV -2 ).

MUS

mobility at zero substrate bias and at V ds =V dd (in cm 2 /V 2 s).

X2MS*

sens. of mobility to substrate bias at V ds =V dd (in cm 2 /V 2 s).

X3MS*

sens. of mobility to drain bias at V ds =V dd (in cm 2 /V 2 s).

X3U1*

sens. of velocity saturation effect on drain bias at V ds =V dd (in μmV -2 ).

TOX

gate oxide thickness (in μm).

TEMP

temperature at which parameters were measured (in °C)

VDD

measurement bias range (in Volts).

CGDO

gate-drain overlap capacitance per meter channel width (in F/m).

CGSO

gate-source overlap capacitance per meter channel width (in F/m).

CGBO

gate-bulk overlap capacitance per meter channel length (in F/m).

XPART

gate-oxide capacitance-charge model flag.

N0*

zero-bias sub-threshold slope coefficient.

NB*

sens. of sub-threshold slope to substrate bias.

ND*

sens. of sub-threshold slope to drain bias.

RSH

drain and source diffusion sheet resistance (in Ohms).

JS

source drain junction current density (in A/m 2 ).

PB

built-in potential of source drain junction (in Volts).

MJ

grading coefficient of source drain junction.

PBSW

built-in potential of source drain junction sidewall (in Volts).

MJSW

grading coefficient of source drain junction sidewall.

CJ

source drain junction capacitance per unit area (in F/m 2 ).

CJSW

source drain junction sidewall capacitance per unit length (in F/m).

WDF

source drain junction default width (in meters).

DELL

source drain junction length reduction (in meters).

The following is a list of parameters that can be stored in the associated model file, when using the BSIM3 model:

LEVEL

model index (Default = 1).

MOBMOD

mobility model selector (Default = 1).

CAPMOD

flag for the short-channel capacitance model (Default = 2).

NQSMOD

flag for NQS model (Default = 0).

NOIMOD

flag for noise model (Default = 1).

VTH0

threshold voltage (at V BS =0) for Large L (in Volts). (Default = 0.7 - NMOS; -0.7 - PMOS). (See BSIM3-Related notes).

K1

first-order body effect coefficient (in V 1/2 ). (Default = 0.5). (See BSIM3-Related notes).

K2

second-order body effect coefficient (Default = 0). (See BSIM3-Related notes).

K3

narrow width coefficient (Default = 80).

K3B

body effect coefficient of K3 (in 1/V). (Default = 0).

W0

narrow width parameter (in meters) (Default = 2.5e-6).

NLX

lateral non-uniform doping parameter (in meters). (Default = 1.74e-7).

VBM

maximum applied body bias in Vth calculation (in Volts). (Default = -3.0).

DVT0

first coefficient of short-channel effect on Vth (Default = 2.2).

DVT1

second coefficient of short-channel effect on Vth (Default = 0.53).

DVT2

body-bias coefficient of short-channel effect on Vth (in 1/V). (Default = -0.032).

DVT0W

first coefficient of narrow width effect on Vth for small channel length (in 1/m). (Default = 0).

DVT1W

second coefficient of narrow width effect on Vth for small channel length (in 1/m). (Default = 5.3e6).

DVT2W

body-bias coefficient of narrow width effect for small channel length (in 1/V). (Default = -0.032).

U0

mobility at TEMP = TNOM (in cm 2 /V/s). (Default = 670.0 - NMOSFET; 250.0 - PMOSFET).

UA

first-order mobility degradation coefficient (in m/V). (Default = 2.25e-9).

UB

second-order mobility degradation coefficient (in (m/V) 2 ). (Default = 5.87e-19).

UC

body-effect of mobility degradation coefficient.
For MOBMOD = 1 or 2, measured in m/V 2 , Default = -4.65e-11
For MOBMOD = 3, measured in 1/V, Default = -0.046.

VSAT

saturation velocity at TEMP = TNOM (in m/sec). (Default = 8.0e4).

A0

bulk charge effect coefficient for channel length (Default = 1.0).

AGS

gate bias coefficient of Abulk (in 1/V). (Default = 0).

B0

bulk charge effect coefficient for channel width (in meters). (Default = 0).

B1

bulk charge effect width offset (in meters). (Default = 0).

KETA

body-bias coefficient of bulk charge effect (in 1/V). (Default = -0.047).

A1

first non-saturation effect parameter (in 1/V). (Default = 0).

A2

second non-saturation factor (Default = 1).

RDSW

parisitic resistance per unit width (in Ω-μm WR ). (Default = 0).

PRWB

body effect coefficient of RDSW (in V -1/2 ). (Default = 0).

PRWG

gate bias effect coefficient of RDSW (in 1/V). (Default = 0).

WR

width offset from Weff for RDS calculation (Default = 1).

WINT

width offset fitting parameter from I-V without bias (in meters). (Default = 0).

LINT

length offset fitting parameter from I-V without bias (in meters). (Default = 0).

DWG

coefficient of Weff's gate dependence (in m/V). (Default = 0).

DWB

coefficient of Weff's substrate body-bias dependence (in m/V 1/2 ). (Default = 0).

VOFF

offset voltage in the subthreshold region at large W and L (in Volts). (Default = -0.08).

NFACTOR

subthreshold swing factor (Default = 1).

ETA0

DIBL coefficient in subthreshold region (Default = 0.08).

ETAB

body-bias coefficient for the subthreshold DIBL effect (in 1/V). (Default = -0.07).

DSUB

DIBL coefficient exponent in subthreshold region (Default = DROUT).

CIT

interface trap capacitance (in F/m 2 ). (Default = 0).

CDSC

Drain/Source to channel coupling capacitance (in F/m 2 ). (Default = 2.4e-4).

CDSCB

body-bias sensitivity of CDSC (in F/Vm 2 ). (Default = 0).

CDSCD

Drain-bias sensitivity of CDSC (in F/Vm 2 ). (Default = 0).

PCLM

channel length modulation parameter (Default = 1.3).

PDIBLC1

first output resistance DIBL effect correction parameter (Default = 0.39).

PDIBLC2

second output resistance DIBL effect correction parameter (Default = 0.0086).

PDIBLCB

body-effect coefficient of DIBL correction parameters (in 1/V). (Default = 0).

DROUT

L dependence coefficient of the DIBL correction parameter in Rout (Default = 0.56).

PSCBE1

first substrate current body-effect parameter (in V/m). (Default = 4.24e8).

PSCBE2

second substrate current body-effect parameter (in m/V). (Default = 1.0e-5).

PVAG

gate dependence of Early voltage (Default = 0).

DELTA

Effective Vds parameter (in Volts). (Default = 0.01).

NGATE

poly gate doping concentration (in cm -3 ). (Default = 0).

ALPHA0

the first parameter of impact ionization current (in m/V). (Default = 0).

BETA0

the second parameter of impact ionization current (in Volts). (Default = 30).

RSH

source drain sheet resistance (in Ω/square). (Default = 0).

JS

source drain junction saturation current per unit area (in A/m 2 ). (Default = 1.0e-4).

XPART

charge partitioning rate flag (Default = 0).

CGSO

non LDD region source-gate overlap capacitance per channel length (in F/m). (See BSIM3-Related notes).

CGDO

non LDD region drain-gate overlap capacitance per channel length (in F/m). (See BSIM3-Related notes).

CGBO

gate bulk overlap capacitance per unit channel length (in F/m). (Default = 0).

CJ

bottom junction capacitance per unit area (in F/m 2 ). (Default = 5e-4).

MJ

bottom junction capacitance grating coefficient (Default = 0.5).

MJSW

Source/Drain side junction capacitance grading coefficient (Default = 0.33).

CJSW

Source/Drain side junction capacitance per unit area (in F/m). (Default = 5e-10).

CJSWG

Source/Drain gate sidewall junction capacitance grading coefficient (in F/m). (Default = CJSW).

MJSWG

Source/Drain gate sidewall junction capacitance coefficient. (Default = MJSW).

PBSW

Source/Drain side junction built-in potential (in Volts). (Default = 1.0).

PB

bottom built-in potential (in Volts). (Default = 1.0).

PBSWG

Source/Drain gate sidewall junction built-in potential (in Volts). (Default = PBSW).

CKAPPA

coefficient for lightly doped region overlap capacitance (in F/m). (Default = 0.6).

CF

Fringing field capacitance (in F/m). (See BSIM3-Related notes).

CLC

constant term for the short channel model (in meters). (Default = 0.1e-6).

CLE

exponential term for the short channel model (Default = 0.6).

DLC

length offset fitting parameter from C-V (in meters). (Default = LINT).

DWC

width offset fitting parameter from C-V (in meters). (Default = WINT).

ELM

Elmore constant of the channel (Default = 5).

WL

coefficient of length dependence for width offset (in m WLN ). (Default = 0).

WLN

power of length dependence for width offset (Default = 1.0).

WW

coefficient of width dependence for width offset (in m WWN ). (Default = 0).

WWN

power of width dependence for width offset (Default = 1.0).

WWL

coefficient of length and width cross term for width offset (in m WWN+WLN ). (Default = 0).

LL

coefficient of length dependence for length offset (in m LLN ). (Default = 0).

LLN

power of length dependence for length offset (Default = 1.0).

LW

coefficient of width dependence for length offset (in m LWN ). (Default = 0).

LWN

power of width dependence for length offset (Default = 1.0).

LWL

coefficient of length and width cross term for length offset (in m LWN+LLN ). (Default = 0).

TNOM

parameter measurement temperature (in °C) 
- If no value is specified, the default value assigned to TNOM on the SPICE Options page of the Analyses Setup dialog will be used (Default = 27).

UTE

mobility temperature exponent (Default = -1.5).

KT1

temperature coefficient for threshold voltage (in Volts). (Default = -0.11).

KT1L

channel length dependence of the temperature coefficient for threshold voltage (in V*m). (Default = 0).

KT2

body-bias coefficient of Vth temperature effect (Default = 0.022).

UA1

temperature coefficient for UA (in m/V). (Default = 4.31e-9).

UB1

temperature coefficient for UB (in (m/V) 2 ). (Default = -7.61e-18).

UC1

temperature coefficient for UC.
For MOBMOD = 1 or 2, measured in m/V 2 , Default = -5.6e-11
For MOBMOD = 3, measured in 1/V, Default = -0.056.

AT

temperature coefficient for saturation velocity (in m/s). (Default = 3.3e4).

PRT

temperature coefficient for RDSW (in Ω-μm). (Default = 0).

NJ

emission coefficient of junction (Default = 1).

XTI

junction current temperature exponent coefficient (Default = 3.0).

NOIA

noise parameter A (Default = 1e20 - NMOS; 9.9e18 - PMOS).

NOIB

noise parameter B (Default = 5e4 - NMOS; 2.4e3 - PMOS).

NOIC

noise parameter C (Default = -1.4e-12 - NMOS; 1.4e-12 - PMOS).

EM

saturation field (in V/m). (Default = 4.1e7).

AF

frequency exponent (Default = 1).

EF

flicker exponent (Default = 1).

KF

flicker noise parameter (Default = 0).

TOX

gate oxide thickness (in meters). (Default = 1.5e-8).

XJ

junction depth (in meters). (Default = 1.5e-7).

GAMMA1

body-effect coefficient near the surface (in V 1/2 ). (See BSIM3-Related notes).

GAMMA2

body-effect coefficient in the bulk (in V 1/2 ). (See BSIM3-Related notes).

NCH

channel doping concentration (in 1/cm 3 ). (Default = 1.7e17). (See BSIM3-Related notes).

NSUB

substrate doping concentration (in 1/cm 3 ). (Default = 6e16).

VBX

Vbs at which the depletion region width equals XT (in Volts). (See BSIM3-Related notes).

XT

doping depth (in meters). (Default = 1.55e-7).

LMIN

minimum channel length (in meters). (Default = 0).

LMAX

maximum channel length (in meters). (Default = 1.0).

WMIN

minimum channel width (in meters). (Default = 0).

WMAX

maximum channel width (in meters). (Default = 1.0).

BINUNIT

Bin unit scale selector (Default = 1).

The following is a list of parameters that can be stored in the associated model file, when using the EKV model:

Process Related Parameters

COX

gate oxide capacitance per unit area (in F/m 2 ). (Default = 0.7e-3).

XJ

junction depth (in meters). (Default = 0.1e-6).

DW

channel width correction (in meters). (Default = 0).

DL

channel length correction (in meters). (Default = 0).

Basic Intrinsic Model Parameters

VTO

long-channel threshold voltage (in Volts). (Default = 0.5).

GAMMA

body effect parameter (in V 1/2 ). (Default = 1.0).

PHI

bulk Fermi potential (*2) (in Volts). (Default = 0.7).

KP

transconductance parameter (in A/V 2 ). (Default = 50.0e-6).

E0 (EO)

mobility reduction coefficient (in V/m). (Default = 1.0e12).

UCRIT

longitudinal critical field (in V/m). (Default = 2.0e6).

Optional Parameters

TOX

oxide thickness (in meters).

NSUB

channel doping (in cm -3 ).

VFB

flat-band voltage (in Volts).

UO

low-field mobility (in cm 2 /Vs).

VMAX

saturation velocity (in m/s).

THETA

mobility reduction coefficient (in 1/V). (Default = 0).

Channel Length Modulation and Charge Sharing Parameters

LAMBDA

depletion length coefficient (channel length modulation). (Default = 0.5).

WETA

narrow-channel effect coefficient. (Default = 0.25).

LETA

short-channel effect coefficient. (Default = 0.1).

Reverse Short-Channel Effect Parameters

Q0 (QO)

reverse short-channel effect peak charge density (in As/m 2 ). (Default = 0).

LK

reverse short-channel effect characteristic length (in meters). (Default = 0.29e-6).

Impact Ionization Related Parameters

IBA

first impact ionization coefficient (in 1/m). (Default = 0).

IBB

second impact ionization coefficient (in V/m). (Default = 3.0e8).

IBN

saturation voltage factor for impact ionization. (Default = 1.0).

Intrinsic Model Temperature Parameters

TCV

threshold voltage temperature coefficient (in V/K). (Default = 1.0e-3).

BEX

mobility temperature exponent. (Default = -1.5).

UCEX

longitudinal critical field temperature exponent. (Default = 0.8).

IBBT

temperature coefficient for IBB (in 1/K). (Default = 9.0e-4).

Flicker Noise Parameters

KF

flicker noise coefficient. (Default = 0).

AF

flicker noise exponent. (Default = 1).

Setup Parameters

NQS

non-quasi-static (NQS) operation switch. (Default = 0).

SATLIM

ratio defining the saturation limit. (Default = exp(4)).

Additional Parameters

LEVEL

model index (Default = 1).

TNOM

parameter measurement temperature (in °C) 
- If no value is specified, the default value assigned to TNOM on the SPICE Options page of the Analyses Setup dialog will be used (Default = 27).

IS

bulk junction saturation current (in Amps). (Default = 1.0e-14).

JS

bulk junction saturation current per square meter of junction area (in Amps/m 2 ).

JSW

sidewall saturation current per unit length (in A/m). (Default = 0).

N

bulk p-n emission coefficient. (Default = 1).

CBD

zero-bias B-D junction capacitance (in Farads). (Default = 0).

CBS

zero-bias B-S junction capacitance (in Farads). (Default = 0).

CJ

zero-bias bulk junction bottom capacitance per square meter of junction area (in Farads/m 2 ). (Default = 0).

CJSW

zero-bias bulk junction sidewall capacitance per meter of junction perimeter (in Farads/meter). (Default = 0).

MJ

bulk junction bottom grading coefficient. (Default = 0.5).

MJSW

bulk junction sidewall grading coefficient. (Default = 0.33).

FC

coefficient for forward-bias depletion capacitance formula. (Default = 0.5).

PB

bulk junction potential (in Volts). (Default = 0.8).

PBSW

built-in potential of source drain junction sidewall (in Volts). (Default = 1).

TT

bulk p-n transit time (in seconds). (Default = 0).

CGSO

Gate-Source overlap capacitance per meter channel width (in F/m). (Default = 0).

CGDO

Gate-Drain overlap capacitance per meter channel width (in F/m). (Default = 0).

CGBO

Gate-Bulk overlap capacitance per meter channel length (in F/m). (Default = 0).

RD

drain ohmic resistance (in Ohms). (Default = 0).

RS

source ohmic resistance (in Ohms). (Default = 0).

RSH

Drain and Source diffusion sheet resistance (in Ohms). (Default = 0).

RSC

source contact resistance (in Ohms). (Default = 0).

RDC

drain contact resistance (in Ohms). (Default = 0).

XTI

drain, source junction current temperature exponent. (Default = 0).

TR1

first-order temperature coefficient for drain, source series resistance (in °C -1 ). (Default = 0).

TR2

second-order temperature coefficient for drain, source series resistance (in °C -1 ). (Default = 0).

ACM

area calculation model. (Default = 0).

CJGATE

zero-bias gate-edge sidewall junction capacitance (in F/m). If no value is specified, the value assigned to CJSW will be used. This parameter is only used when ACM = 3. It is ignored otherwise.

GEO

shared geometry parameter. (Default = 0). This parameter is only used when ACM = 3. It is ignored otherwise.

HDIF

length of heavily doped diffusion (in m). (Default = 0). This parameter is only used when ACM = 2 or 3. It is ignored otherwise.

LD

lateral diffusion into channel (in m). (Default = 0).

LDIF

length of lightly doped diffusion near gate (in m). (Default = 0).

SCALM

model scaling factor. (Default = 1).

UPDATE

selects effective drain and source resistance model. (Default = 0). This parameter is only used when ACM = 1. It is ignored otherwise.

WMLT

width diffusion layer shrink reduction factor. (Default = 1).

Notes

General

  1. The Simulator supports the following MOSFET device models, which differ only in their formulation of the I-V characteristic:
  • Shichman-Hodges (LEVEL=1)
  • MOS2 (LEVEL=2)
  • MOS3 (LEVEL=3)
  • BSIM (LEVEL=4)
  • BSIM2 (LEVEL=5)
  • MOS6 (LEVEL=6)
  • BSIM3 (LEVEL=7)
  • EKV (LEVEL=8)
  1. The LEVEL parameter is used to specify which model to use. It is declared at the start of the parameter values list, entered in the associated model file. If no LEVEL parameter is declared, the default Schichman-Hodges model will be used.
  2. The Bulk (substrate) node is connected, by default, to the Source node.
  3. If any of the component-level Length, Width, Drain Area or Source Area parameters are not specified, default values will be used.
  4. The values for the component-level NRD and NRS parameters are used to multiply the sheet resistance (RSH), in order to obtain an accurate representation of the parasitic series drain and source resistance of each transistor.
  5. The values for the component-level parameters Initial D-S Voltage, Initial G-S Voltage and Initial B-S Voltage only apply if the Use Initial Conditions option is enabled on the Transient/Fourier Analysis Setup page of the Analyses Setup dialog.
  6. The component-level Temperature parameter applies to LEVEL 1,2,3,6 & 8 MOSFET models (not BSIM type models).
  7. The link to the required model file (*.mdl) is specified on the Model Kind tab of the Sim Model dialog. The Model Name is used in the netlist to reference this file.
  8. Where a parameter has an indicated default (as part of the SPICE model definition), that default will be used if no value is specifically entered. The default should be applicable to most simulations. Generally you do not need to change this value.

BSIM/BSIM2-Related

  1. The BSIM and BSIM2 models are designed to be used with a process characterization system. This system is responsible for providing all parameter information (values) automatically through the use of a process file and therefore no default parameter values are specified. As a consequence, all parameters are required to be specified and the absence of any will result in an error.
  2. If the XPART parameter is set to 0, a 40/60 drain/source charge partition in saturation is selected. If this parameter is set to 1, a 0/100 drain/source charge partition is selected.
  3. Certain model parameters (those marked with an asterisk in the BSIM/BSIM2 list of parameters) also have corresponding parameters dependent on length and width. For more information on these and other aspects of the MOSFET models, consult the SPICE reference manual.

BSIM3-Related

  1. The following charge partition schemes are supported, selectable based on the value entered for the XPART parameter:
  • XPART = 0 - a 0/100 drain/source charge partition os selected
  • XPART = 0.5 - a 50/50 drain/source charge partition os selected
  • XPART = 1 - a 40/60 drain/source charge partition os selected.
  1. If no value is specified for one of the following parameters, it will be calculated:
  • VTH0
  • K1
  • K2
  • CGSO
  • CGDO
  • CF
  • GAMMA1
  • GAMMA2
  • NCH
  • VBX
  1. For details of the calculations involved, refer to the BSIM3v3 User Manual.
  2. The following BSIM3 model parameters are not supported in Altium Designer:

JSSW

side wall saturation current density.

CGS1

light doped source-gate region overlap capacitance.

CGD1

light doped drain-gate region overlap capacitance.

VFB

flat-band volatge parameter.

EKV-Related

  1. The EKV MOSFET model was developed by the Electronics Laboratory (LEG) of the Swiss Federal Institute of Technology (EPFL). The model used in Altium Designer is version 2.6.
  2. The following EKV model parameters are not supported in Altium Designer:

M or NP

parallel multiple device number.

N or NS

series multiple device number.

AVTO

area related threshold voltage mismatch parameter.

AKP

area related gain mismatch parameter.

AGAMMA

area related body effect mismatch parameter.

XQC

charge/capacitance model selector.

For more detailed information on model equations associated with the EKV MOSFET, search the site http://ekv.epfl.ch/ for the document The EPFL-EKV MOSFET Model Equations for Simulation

Examples

Consider the MOSFET in the above image, with the following characteristics:

  • Pin1 (Drain) is connected to net D
  • Pin2 (Gate) is connected to net G
  • Pin3 (Source) is connected to net S
  • The substrate node (Bulk) is connected to Pin3 (the Source node).
  • Designator is Q1
  • The linked simulation model file is NMOS3.mdl.

If no values are entered for the parameters in the Sim Model dialog, the entries in the SPICE netlist would be:

*Schematic Netlist:
MQ1 D G S S NMOS3 
.
.
*Models and Subcircuit:
.MODEL NMOS3 NMOS(LEVEL=3)

In this case, there are no parameter values specified in the Sim Model dialog. In the model file, there is only the LEVEL parameter specified, corresponding to the use of the MOS3 model. The default values for all other parameters inherent to the model will be used.

PSpice Support

Of the existing MOSFET device models, the following are not supported with respect to PSpice compatibility:

  • BSIM3 model version 2.0

For the other supported MOSFET device models, many of the parameters that can be included in a linked model file are common to both Spice3f5 and PSpice. Those that are supported can be found in the previous section, Parameters (definable within model file).

The following PSpice-based parameters are not supported for this device type.

GDSNOI

channel shot noise coefficient (use with NLEV=3)

JSSW

bulk p-n saturation sidewall current/length

L

channel length

N

bulk p-n emission coefficient

NLEV

noise equation selector

PBSW

bulk p-n sidewall potential

RB

bulk ohmic resistance

RDS

drain-source shunt resistance

RG

gate ohmic resistance

TT

bulk p-n transit time

W

channel width

 

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