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N-Channel MOSFET

N-Channel metal oxide semiconductor field effect transistor using either Shichman-Hodges equation or surface-potential-based model

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  • N-Channel MOSFET block

Description

The N-Channel MOSFET block provides two main modeling options:

  • Based on threshold voltage — Uses the Shichman-Hodges equation to represent the device. This modeling approach, based on threshold voltage, has the benefits of simple parameterization and simple current-voltage expressions. However, these models have difficulty in accurately capturing transitions across the threshold voltage and lack some important effects, such as velocity saturation. For details, see Threshold-Based Model.

    This modeling option provides four ways of parameterizing an N-Channel MOSFET:

    • By specifying parameters from a datasheet.

    • By specifying equation parameters directly.

    • By a 2-D lookup table approximation to the I-V (current-voltage) curve. For details, see Representation by 2-D Lookup Table.

    • By a 3-D lookup table approximation to the I-V (current-voltage) curve that includes temperature data. For details, see Representation by 3-D Lookup Table.

  • Based on surface potential — Uses the surface-potential equation to represent the device. This modeling approach provides a greater level of model fidelity than the simple square-law (threshold-voltage-based) models can provide. The trade-off is that there are more parameters that require extraction. For details, see Surface-Potential-Based Model.

Together with the thermal port options (see Thermal Port), the block therefore provides you with four choices. To select the desired option, set the Modeling option parameter to either:

  • Threshold-based — Basic model, which represents the device using the Shichman-Hodges equation (based on threshold voltage) and does not simulate thermal effects. This is the default.

  • Threshold-based with thermal — Model based on threshold voltage and with exposed thermal port.

  • Surface-potential-based — Model based on surface potential. This model does not simulate thermal effects.

  • Surface-potential-based with thermal — Thermal modeling option of the model based on surface potential.

Threshold-Based Model

The threshold-based option of the block uses the Shichman and Hodges equations [1] for an insulated-gate field-effect transistor to represent an N-Channel MOSFET.

The drain-source current, IDS, depends on the region of operation:

  • In the off region (VGS < Vth), the drain-source current is:

    IDS=0

  • In the linear region (0 < VDS < VGSVth), the drain-source current is:

    IDS=K((VGSVth)VDSVDS2/2)(1+λ|VDS|)

  • In the saturated region (0 < VGSVth < VDS), the drain-source current is:

    IDS=(K/2)(VGSVth)2(1+λ|VDS|)

In the preceding equations:

  • K is the transistor gain.

  • VDS is the positive drain-source voltage.

  • VGS is the gate-source voltage.

  • Vth is the threshold voltage. For the four terminal parameterization, Vth is obtained using these equations:

    VBS RangeVth Equation
    VBS0Vth=VT0+γ(2ϕB)+γ(2ϕBVBS)
    0<VBS4ϕBVth=VT0γVBS2ϕB
    VBS>4ϕBVth=VT0+γ(2ϕB)

  • λ is the channel modulation.

Charge Model for Threshold-Based Modeling Option

The block models junction capacitances either by fixed capacitance values, or by tabulated values as a function of the drain-source voltage. In either case, you can either directly specify the gate-source and gate-drain junction capacitance values, or let the block derive them from the input and reverse transfer capacitance values. Therefore, the Parameterization options for charge model on the Capacitance setting are:

  • Specify fixed input, reverse transfer and output capacitance — Provide fixed parameter values from datasheet and let the block convert the input and reverse transfer capacitance values to junction capacitance values, as described below. This is the default method.

  • Specify fixed gate-source, gate-drain and drain-source capacitance — Provide fixed values for junction capacitance parameters directly.

  • Specify tabulated input, reverse transfer and output capacitance — Provide tabulated capacitance and drain-source voltage values based on datasheet plots. The block converts the input and reverse transfer capacitance values to junction capacitance values, as described below.

  • Specify tabulated gate-source, gate-drain and drain-source capacitance — Provide tabulated values for junction capacitances and drain-source voltage.

Use one of the tabulated capacitance options (Specify tabulated input, reverse transfer and output capacitance or Specify tabulated gate-source, gate-drain and drain-source capacitance) when the datasheet provides a plot of junction capacitances as a function of drain-source voltage. Using tabulated capacitance values gives more accurate dynamic characteristics and avoids the need for interactive tuning of parameters to fit the dynamics.

If you use the Specify fixed gate-source, gate-drain and drain-source capacitance or Specify tabulated gate-source, gate-drain and drain-source capacitance option, the Capacitance setting lets you specify the Gate-drain junction capacitance, Gate-source junction capacitance, and Drain-source junction capacitance parameter values (fixed or tabulated) directly. Otherwise, the block derives them from the Input capacitance, Ciss, Reverse transfer capacitance, Crss, and Output capacitance, Coss parameter values. These two parameterization methods are related as follows:

  • CGD = Crss

  • CGS = CissCrss

  • CDS = CossCrss

For the four terminals parameterization, the Input capacitance, Ciss, Reverse transfer capacitance, Crss, and Output capacitance, Coss are obtained using these equations:

  • CGD = Crss

  • CGS + CGB = CissCrss

  • CDB = CossCrss

A simplified Meyer's capacitance model is used to describe the gate-source capacitance, CGS, the gate-bulk capacitance, CGB, and the gate-drain capacitance, CGD. These figures show how the gate-bulk and gate-source capacitances change instantaneously, while the

Gate-bulk and gate-source capacitance change instantaneously.

The two fixed capacitance options (Specify fixed input, reverse transfer and output capacitance or Specify fixed gate-source, gate-drain and drain-source capacitance) let you model gate junction capacitance as a fixed gate-source capacitance CGS and either a fixed or a nonlinear gate-drain capacitance CGD. If you select the Gate-drain charge function is nonlinear option for the Gate-drain charge-voltage linearity parameter, then the gate-drain charge relationship is defined by the piecewise-linear function shown in the following figure.

For instructions on how to map a time response to device capacitance values, see the N-Channel IGBT block reference page. However, this mapping is only approximate because the Miller voltage typically varies more from the threshold voltage than in the case for the IGBT.

Note

Because this block implementation includes a charge model, you must model the impedance of the circuit driving the gate to obtain representative turn-on and turn-off dynamics. Therefore, if you are simplifying the gate drive circuit by representing it as a controlled voltage source, you must include a suitable series resistor between the voltage source and the gate.

Representation by 2-D Lookup Table

For the lookup table representation of the detailed block modeling option, you provide tabulated values for drain-source currents as a function of gate-source voltage and drain-source voltage. The main advantage of using this option is simulation speed. It also lets you parameterize the device from either measured data or from data obtained from another simulation environment.

This figure shows the implementation of the 2-D lookup table option when you set Ids-Vds parameterization to Provide negative and positive Vds data:

This figure shows the implementation of the 2-D lookup table option when you set Ids-Vds parameterization to Provide positive Vds data only:

For the four terminal MOSFET, the surface potential and body factor values are calculated based on the nearest threshold voltage as shown in this picture:

Representation by 3-D Lookup Table

For the temperature-dependent lookup table representation of the detailed block modeling option, you provide tabulated values for drain-source currents as a function of gate-source voltage, drain-source voltage, and temperature.

Surface-Potential-Based Model

The surface-potential-based modeling option of the block provides a greater level of model fidelity than the simple square-law (threshold-voltage-based) model. The surface-potential-based block modeling option includes the following effects:

  • Fully nonlinear capacitance model (including the nonlinear Miller capacitance)

  • Charge conservation inside the model, so you can use the model for charge sensitive simulations

  • Velocity saturation and channel-length modulation

  • The intrinsic body diode

  • Reverse recovery in the body diode model

  • Temperature scaling of physical parameters

  • For the thermal modeling option, dynamic self-heating (that is, you can simulate the effect of self-heating on the electrical characteristics of the device)

This model is a minimal version of the world-standard PSP model (see https://briefs.techconnect.org/papers/introduction-to-psp-mosfet-model/), including only certain effects from the PSP model in order to strike a balance between model fidelity and complexity. For details of the physical background to the phenomena included in this model, see [2].

The basis of the model is Poisson equation:

2ψx2+2ψy2=qNAεSi[1exp(ψϕT)+exp(ψ2ϕBVCBϕT)]

ϕT=kBTq

where:

  • ψ is the electrostatic potential.

  • q is the magnitude of the electronic charge.

  • NA is the density of acceptors in the substrate.

  • ɛSi is the dielectric permittivity of the semiconductor material (for example, silicon).

  • ϕB is the difference between the intrinsic Fermi level and the Fermi level in the bulk silicon.

  • VCB is the quasi-Fermi potential of the surface layer referenced to the bulk.

  • ϕT is the thermal voltage.

  • kB is Boltzmann’s constant.

  • T is temperature.

Poisson equation is used to derive the surface-potential equation:

(VGBVFBψs)2=γ2[ψs+ϕT(exp(ψsϕT)1)+ϕTexp(2ϕB+VCBϕT)(exp(ψsϕT)1)]

where:

  • VGB is the applied gate-body voltage.

  • VFB is the flatband voltage.

  • ψs is the surface potential.

  • γ is the body factor,

γ=2qεSiNACox

  • Cox is the capacitance per unit area.

The block uses an explicit approximation to the surface-potential equation, to avoid the need for numerical solution to this implicit equation.

Once the surface potential is known, the drain current ID is given by

ID=Wμ0LGΔLGmob1+(θsatΔψ)2[Q¯invΔψ+ϕT(QinvLQinv0)]

where:

  • W is the device width.

  • L is the channel length.

  • μ0 is the low-field mobility.

  • θsat is the velocity saturation.

  • Δψ is the difference in the surface potential between the drain and the source.

  • Qinv0 and QinvL are the inversion charge densities at the source and drain, respectively.

  • Q¯inv is the average inversion charge density across the channel.

  • Gmob is the mobility reduction factor. For more information, see the Surface roughness scattering factor parameter description in the Main (Surface-Potential-Based Modeling Option) section.

  • GΔL is the channel-length modulation.

GΔL=1ΔLL=1αln[VDBVDB,eff+(VDBVDB,eff)2+Vp2Vp]

where:

  • α is the channel-length modulation factor.

  • VDB is the drain-body voltage.

  • VDB,eff is the drain-body voltage clipped to a maximum value corresponding to velocity saturation or pinch-off (whichever occurs first).

  • Vp is the channel-length modulation voltage.

The block computes the inversion charge densities directly from the surface potential.

The block also computes the nonlinear capacitances from the surface potential. Source and drain charge contributions are assigned via a bias-dependent Ward-Dutton charge-partitioning scheme, as described in [3]. These charges are computed explicitly, so this model is charge-conserving. The capacitive currents are computed by taking the time derivatives of the relevant charges. In practice, the charges within the simulation are normalized to the oxide capacitance and computed in units of volts.

The MOSFET gain, β, is given by

β=Wμ0CoxL

The threshold voltage for a short-circuited source-bulk connection is approximately given by

VT=VFB+2ϕB+2ϕT+γ2ϕB+2ϕT

where:

  • 2ϕB is the surface potential at strong inversion.

The overall three and four terminal models consist of an intrinsic MOSFET defined by the surface-potential formulation, a body diode, series resistances, and fixed overlap capacitances, as shown in the schematics.

Modeling Body Diode

The block models the body diode either as an ideal, exponential diode or as a tabulated diode.

Exponential Diode

When you set Model body diode to Exponential, the junction and diffusion capacitances are:

Idio=Is[exp(VDBnϕT)1]

Cj=Cj01+VDBVbi

Cdiff=τIsnϕTexp(VDBnϕT)

where:

  • Idio is the current through the diode.

  • Is is the reverse saturation current.

  • VDB is the drain-body voltage.

  • n is the ideality factor.

  • ϕT is the thermal voltage.

  • Cj is the junction capacitance of the diode.

  • Cj0 is the zero-bias junction capacitance.

  • Vbi is the built-in voltage.

  • Cdiff is the diffusion capacitance of the diode.

  • τ is the transit time.

The capacitances are defined through an explicit calculation of charges, which are then differentiated to give the capacitive expressions above. The block computes the capacitive diode currents as time derivatives of the relevant charges, similar to the computation in the surface-potential-based MOSFET model.

Tabulated Diode

To model a tabulated diode, set the Model body diode parameter to Tabulated I-V curve. This figure shows the implementation of the tabulated diode option:

When choosing this parameterization, you must provide the data for the forward bias only.

The block implements the diode using a smooth interpolation option. If the diode exceeds the provided tabulated data range, the block uses a linear extrapolation technique at the last voltage-current data point.

Note

The tabulated diode does not model the reverse breakdown.

Modeling Temperature Dependence

The default behavior is that dependence on temperature is not modeled, and the device is simulated at the temperature for which you provide block parameters. To model the dependence on temperature during simulation, select Model temperature dependence for the Parameterization parameter in the Temperature Dependence setting.

Threshold-Based Model

For threshold-based modeling option, you can include modeling the dependence of the transistor static behavior on temperature during simulation. Temperature dependence of the junction capacitances is not modeled, this being a much smaller effect.

When including temperature dependence, the transistor defining equations remain the same. The gain, K, and the threshold voltage, Vth, become a function of temperature according to the following equations:

KTs=KTm1(TsTm1)BEX

Vths = Vth1 + α (TsTm1)

where:

  • Tm1 is the temperature at which the transistor parameters are specified, as defined by the Measurement temperature parameter value.

  • Ts is the simulation temperature.

  • KTm1 is the transistor gain at the measurement temperature.

  • KTs is the transistor gain at the simulation temperature. This is the transistor gain value used in the MOSFET equations when temperature dependence is modeled.

  • Vth1 is the threshold voltage at the measurement temperature.

  • Vths is the threshold voltage at the simulation temperature. This is the threshold voltage value used in the MOSFET equations when temperature dependence is modeled.

  • BEX is the mobility temperature exponent. A typical value of BEX is -1.5.

  • α is the gate threshold voltage temperature coefficient, dVth/dT.

For the four terminals parameterization, Vth is obtained using these equations:

VBS RangeVth Equation
VBS0dVthdT=dVT0dTγ22ϕBd2ϕBdT+γ22ϕBVBSd2ϕBdT
0<VBS4ϕBdVthdT=dVT0dTγVBS4(2ϕB)32d2ϕBdT
VBS>4ϕBdVthdT=dVT0dTγ22ϕBd2ϕBdT

Where:

  • ϕB=kTqln(NBni) is the surface potential and d2ϕBdT=1T[2ϕB(Eg(0)q+3kTq)].

  • Eg(0) is the extrapolated zero degree band-gap, which is equal to 1.16 eV for silicon.

  • VBS is the bulk-source voltage.

For most MOSFETS, you can use the default value of -1.5 for BEX. Some datasheets quote the value for α, but most typically they provide the temperature dependence for drain-source on resistance, RDS(on). Depending on the block parameterization method, you have two ways of specifying α:

  • If you parameterize the block from a datasheet, you have to provide RDS(on) at a second measurement temperature. The block then calculates the value for α based on this data.

  • If you parameterize by specifying equation parameters, you have to provide the value for α directly.

If you have more data comprising drain current as a function of gate-source voltage for more than one temperature, then you can also use Simulink® Design Optimization™ software to help tune the values for α and BEX.

Surface-Potential-Based Model

The surface-potential-based model includes temperature effects on the capacitance characteristics, as well as modeling the dependence of the transistor static behavior on temperature during simulation.

The Measurement temperature parameter on the Main setting specifies temperature Tm1 at which the other device parameters have been extracted. The Temperature Dependence setting provides the simulation temperature, Ts, and the temperature-scaling coefficients for the other device parameters. For more information, see Temperature Dependence (Surface-Potential-Based Modeling Option).

Faults

The N-Channel MOSFET block models five types of fault:

  • Open circuit — Failure due to metallization burnout

  • Drain-source short — Failure due to avalanche breakdown on drain-source channel

  • Drain-bulk short or source-bulk short — Failure due to avalanche breakdown on drain-bulk or source-bulk channels

  • Gate oxide short — Failure of the gate oxide dielectric layer

  • Parameter shift — Failure due to aging

The block can trigger fault events at a specific time or when the current or voltage exceed the limit for longer than a specific time interval.

To enable these trigger mechanisms, set the Fault trigger parameter to either Temporal or Behavioral.

Parameter Shift Fault

If, in the Faults settings, you set the Failure mode parameter to Parameter shift, the MOSFET fails due to the aging of its components. This equation defines the value of the shifted parameters:

Parameter(t)=Parameterfaulted(ParameterfaultedParameterunfaulted)sech(ttthτ),

where tth is the time threshold when the fault is triggered and τ is the value of the Fault transition time constant, tau parameter.

Gate Oxide Short Fault

If, in the Faults settings, you set the Failure mode parameter to Gate oxide short, the gate oxide dielectric layer fails. These figures show the equivalent circuits for the three terminal or four terminal MOSFET in the unfaulted and faulted state:

Thermal Port

The block has an optional thermal port, hidden by default. To expose the thermal port, set the Modeling option parameter to:

  • Threshold-based with thermal — Model based on threshold voltage and with exposed thermal port

  • Surface-potential-based with thermal — Model based on surface potential and with exposed thermal port

This action displays the thermal port H on the block icon, and exposes the Thermal Port parameters.

Use the thermal port to simulate the effects of generated heat and device temperature. For more information on using thermal ports and on the Thermal Port parameters, see Simulating Thermal Effects in Semiconductors.

Assumptions and Limitations

When modeling temperature dependence for the threshold-based block modeling option, consider the following:

  • The block does not account for temperature-dependent effects on the junction capacitances.

  • When you specify RDS(on) at a second measurement temperature, it must be quoted for the same working point (that is, the same drain current and gate-source voltage) as for the other RDS(on) value. Inconsistent values for RDS(on) at the higher temperature will result in unphysical values for α and unrepresentative simulation results. Typically RDS(on) increases by a factor of about 1.5 for a hundred degree increase in temperature.

  • You may need to tune the values of BEX and threshold voltage, Vth, to replicate the IDSVGS relationship (if available) for a given device. Increasing Vth moves the IDS-–VGS plots to the right. The value of BEX affects whether the IDSVGS curves for different temperatures cross each other, or not, for the ranges of VDS and VGS considered. Therefore, an inappropriate value can result in the different temperature curves appearing to be reordered. Quoting RDS(on) values for higher currents, preferably close to the current at which it will operate in your circuit, will reduce sensitivity to the precise value of BEX.

Ports

Conserving

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Electrical conserving port associated with the transistor gate terminal

Electrical conserving port associated with the transistor drain terminal

Electrical conserving port associated with the transistor source terminal

Electrical conserving port associated with the transistor body terminal

Dependencies

To enable this port, set Parameterization to Four.

Parameters

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Select the MOSFET representation:

  • Threshold-based — Basic model, which represents the device using the Shichman-Hodges equation (based on threshold voltage) and does not simulate thermal effects. This is the default.

  • Threshold-based with thermal — Model based on threshold voltage and with exposed thermal port.

  • Surface-potential-based — Model based on surface potential. This model does not simulate thermal effects.

  • Surface-potential-based with thermal — Thermal modeling option of the model based on surface potential.

Main (Threshold-Based Modeling Option)

This configuration of the Main parameters corresponds to the threshold-based block modeling option, which is the default. If you are using the surface-potential-based modeling option of the block, see Main (Surface-Potential-Based Modeling Option).

Number of terminals of the block.

Select one of the following methods for block parameterization:

  • Specify from a datasheet — Provide the drain-source on resistance and the corresponding drain current and gate-source voltage. The block calculates the transistor gain for the Shichman and Hodges equations from this information.

  • Specify using equation parameters directly — Provide the transistor gain.

  • Lookup table (2-D, temperature independent) — Use 2-D table lookup for drain-source current as a function of gate-source voltage and drain-source voltage.

  • Lookup table (3-D, temperature dependent) — Use 3-D table lookup for drain-source current as a function of gate-source voltage, drain-source voltage, and temperature.

Ratio of the drain-source voltage to the drain current for specified values of drain current and gate-source voltage. RDS(on) should have a positive value.

Dependencies

To enable this parameter, set Parameterization to Specify from a datasheet.

Drain current the block uses to calculate the value of the drain-source resistance. IDS should have a positive value.

Dependencies

To enable this parameter, set Parameterization to Specify from a datasheet.

Gate-source voltage the block uses to calculate the value of the drain-source resistance. VGS should have a positive value.

Dependencies

To enable this parameter, set Parameterization to Specify from a datasheet.

Positive constant gain coefficient for the Shichman and Hodges equations.

Dependencies

To enable this parameter, set Parameterization to Specify using equation parameters directly.

Gate-source threshold voltage Vth in the Shichman and Hodges equations. For an enhancement device, Vth should be positive. For a depletion mode device, Vth should be negative.

Dependencies

To enable this parameter, set Number of terminals to Three and Parameterization to Specify from a datasheet or Specify using equation parameters directly.

Gate-source threshold voltage at zero bulk-source voltage Vth0 in the Shichman and Hodges equations.

Dependencies

To enable this parameter, set Number of terminals to Four and Parameterization to Specify from a datasheet or Specify using equation parameters directly.

The channel-length modulation, usually denoted by the mathematical symbol λ. When in the saturated region, it is the rate of change of drain current with drain-source voltage. The effect on drain current is typically small, and the effect is neglected if calculating transistor gain K from drain-source on-resistance, RDS(on). A typical value is 0.02, but the effect can be ignored in most circuit simulations. However, in some circuits a small nonzero value may help numerical convergence.

Dependencies

To enable this parameter, set Parameterization to Specify from a datasheet or Specify using equation parameters directly.

Gate-source threshold voltage at first non-zero bulk-source voltage Vth1 in the Shichman and Hodges equations.

Dependencies

To enable this parameter, set Number of terminals to Four and Parameterization to Specify from a datasheet.

First bulk-source voltage, Vbs1

Dependencies

To enable this parameter, set Number of terminals to Four and Parameterization to Specify from a datasheet.

Gate-source threshold voltage at second non-zero bulk-source voltage Vth2 in the Shichman and Hodges equations.

Dependencies

To enable this parameter, set Number of terminals to Four and Parameterization to Specify from a datasheet.

Second bulk-source voltage, Vbs2

Dependencies

To enable this parameter, set Number of terminals to Four and Parameterization to Specify from a datasheet.

Body factor, γ.

Dependencies

To enable this parameter, set Number of terminals to Four and Parameterization to Specify using equation parameters directly.

Surface potential.

Dependencies

To enable this parameter, set Number of terminals to Four and Parameterization to Specify using equation parameters directly.

Temperature Tm1 at which Drain-source on resistance, R_DS(on) is measured.

Dependencies

To enable this parameter, set Parameterization to Specify from a datasheet or Specify using equation parameters directly.

Vector of gate-source voltages.

Dependencies

To enable this parameter, set Parameterization to either Lookup table (2-D, temperature independent) or Lookup table (3-D, temperature dependent).

Vector of drain-source voltages, to be used for table lookup. The vector values must be strictly increasing.

Dependencies

To enable this parameter, set Parameterization to either Lookup table (2-D, temperature independent) or Lookup table (3-D, temperature dependent).

Vector of bulk-source voltages, to be used for table lookup.

Dependencies

To enable this parameter, set Number of terminals to Four and Parameterization to either Lookup table (2-D, temperature independent) or Lookup table (3-D, temperature dependent).

Tabulated values for drain-source currents as a function of gate-source voltage and drain-source voltage, to be used for 2-D table lookup. Each value in the matrix specifies the drain-source current for a specific combination of gate-source voltage and drain-source voltage. The matrix size must match the dimensions defined by the gate-source voltage and drain-source voltage vectors.

Dependencies

To enable this parameter, set Number of terminals to Three and Parameterization to Lookup table (2-D, temperature independent).

Vector of temperatures, to be used for table lookup. The vector values must be strictly increasing. The values can be nonuniformly spaced.

Dependencies

To enable this parameter, set Parameterization to Lookup table (3-D, temperature dependent).

Tabulated values for drain-source currents as a function of gate-source voltage, drain-source voltage, and temperature, to be used for 2-D table lookup. Each value in the matrix specifies the drain-source current for a specific combination of gate-source voltage and drain-source voltage. The matrix size must match the dimensions defined by the gate-source voltage, drain-source voltage, and temperature vectors.

Dependencies

To enable this parameter, set Number of terminals to Three and Parameterization to Lookup table (3-D, temperature dependent).

Tabulated values for gate-source threshold voltage as a function of bulk-source voltage, to be used for 2-D table lookup The vector values must be strictly increasing.

Dependencies

To enable this parameter, set Number of terminals to Four and Parameterization to Lookup table (2-D, temperature independent).

Tabulated values for drain-source currents at zero bulk-source voltage, as a function of gate-source voltage and drain-source voltage, to be used for 2-D table lookup. Each value in the matrix specifies the drain-source current for a specific combination of gate-source voltage and drain-source voltage. The matrix size must match the dimensions defined by the gate-source voltage and drain-source voltage vectors.

Dependencies

To enable this parameter, set Number of terminals to Four and Parameterization to Lookup table (2-D, temperature independent).

Tabulated values for gate-source threshold voltage as a function of bulk-source voltage and temperature, to be used for 3-D table lookup The vector values must be strictly increasing.

Dependencies

To enable this parameter, set Number of terminals to Four and Parameterization to Lookup table (3-D, temperature dependent).

Tabulated values for drain-source currents at zero bulk-source voltage, as a function of gate-source voltage, drain-source voltage, and temperature, to be used for 3-D table lookup. Each value in the matrix specifies the drain-source current for a specific combination of gate-source voltage, drain-source voltage, and temperature. The matrix size must match the dimensions defined by the gate-source voltage, drain-source voltage, and temperature vectors.

Dependencies

To enable this parameter, set Number of terminals to Four and Parameterization to Lookup table (3-D, temperature dependent).

Whether to provide Ids-Vds table data as symmetric data. If you choose Provide negative and positive Vds data, the data is not symmetric. If you choose Provide positive Vds data only, the block rotates and flips the positive data to obtain the negative data.

Dependencies

To enable this parameter, set Parameterization to either Lookup table (2-D, temperature independent) or Lookup table (3-D, temperature dependent).

Main (Surface-Potential-Based Modeling Option)

This configuration of the Main setting corresponds to the surface-potential-based block modeling option. If you are using the threshold-based modeling option of the block, based on the Shichman and Hodges equations, see Main (Threshold-Based Modeling Option).

Number of terminals of the block.

MOSFET gain, β. This parameter primarily defines the linear region of operation on an IDVDS characteristic.

Flatband voltage, VFB, defines the gate bias that must be applied in order to achieve the flatband condition at the surface of the silicon. The default value is -1.1 V. You can also use this parameter to arbitrarily shift the threshold voltage due to material work function differences, and to trapped interface or oxide charges. In practice, however, it is usually recommended to modify the threshold voltage by using the Body factor and Surface potential at strong inversion parameters first, and only use this parameter for fine-tuning.

Body factor, γ, in the surface-potential equation. This parameter primarily impacts the threshold voltage.

2ϕB term in the surface-potential equation. This parameter also primarily impacts the threshold voltage.

Velocity saturation, θsat, in the drain-current equation. Use this parameter in cases where a good fit to linear operation leads to a saturation current that is too high. By increasing this parameter value, you reduce the saturation current. For high-voltage devices, it is often the case that a good fit to linear operation leads to a saturation current that is too low. In such a case, either increase both the gain and the drain ohmic resistance or use an N-Channel LDMOS FET block instead.

Factor, α, multiplying the logarithmic term in the GΔL equation. This parameter describes the onset of channel-length modulation. For device characteristics that exhibit a positive conductance in saturation, increase the parameter value to fit this behavior. The default value is 0, which means that channel-length modulation is off by default.

Voltage Vp in the GΔL equation. This parameter controls the drain-voltage at which channel-length modulation starts to become active

Strength of the mobility reduction. The mobility is μ = μ0/Gmob, where μ0 is the low-field mobility without the effect of surface scattering. The mobility reduction factor, Gmob, is given by Gmob=1+(θsrVeff)4, where θsr is the surface roughness scattering factor and Veff is a voltage that is indicative of the effective vertical electric field strength in the channel, Eeff. For high vertical electric fields, the mobility is roughly proportional to Eeff^2 for electrons.

Smoothness of the MOSFET transitions from linear into saturation, particularly when velocity saturation is enabled. This parameter can usually be left at its default value, but you can use it to fine-tune the knee of the IDVDS characteristic. The expected range for this parameter value is between 2 and 8.

Temperature Tm1 at which the block parameters are measured. If the Device simulation temperature parameter on the Temperature Dependence setting differs from this value, then device parameters will be scaled from their defined values according to the simulation and reference temperatures. For more information, see Temperature Dependence (Surface-Potential-Based Modeling Option).

Ohmic Resistance

If you set Modeling option to Threshold-based or Threshold-based with thermal, to enable this setting set Parameterization to Specify from a datasheet or Specify using equation parameters directly.

Transistor source resistance, that is, the series resistance associated with the source contact. The default value for threshold-based variants is 1e-4 Ohm. The default value for surface-potential-based variants is 2e-3 Ohm.

Transistor drain resistance, that is, the series resistance associated with the drain contact. The value must be greater than or equal to 0. The default value for threshold-based variants is 0.01 Ohm. The default value for surface-potential-based variants is 0.17 Ohm.

Transistor gate resistance, that is, the series resistance associated with the gate contact.

Dependencies

To enable this parameter, set Modeling option to Surface-potential-based or Surface-potential-based with thermal.

Transistor body resistance, that is, the series resistance associated with the body contact.

Dependencies

To enable this parameter, set:

  • Number of terminals to Four.

  • Modeling option to Threshold-based or Threshold-based with thermal.

Transistor body resistance, that is, the series resistance associated with the bulk contact.

Dependencies

To enable this parameter, set:

  • Number of terminals to Four.

  • Modeling option to Surface-potential-based or Surface-potential-based with thermal.

Capacitance

To enable this setting, set Modeling option to Threshold-based or Threshold-based with thermal.

Select one of the following methods for capacitance parameterization:

  • Specify fixed input, reverse transfer, and output capacitance — Provide fixed parameter values from datasheet and let the block convert the input, output, and reverse transfer capacitance values to junction capacitance values, as described in Charge Model for Threshold-Based Modeling Option.

  • Specify fixed gate-source, gate-drain, and drain-source capacitance — Provide fixed values for junction capacitance parameters directly.

  • Specify tabulated input, reverse transfer, and output capacitance — Provide tabulated capacitance and drain-source voltage values based on datasheet plots. The block converts the input, output, and reverse transfer capacitance values to junction capacitance values, as described in Charge Model for Threshold-Based Modeling Option.

  • Specify tabulated gate-source, gate-drain, and drain-source capacitance — Provide tabulated values for junction capacitances and drain-source voltage.

Gate-source capacitance with the drain shorted to the source.

Dependencies

To enable this parameter, in the Capacitance setting, set Parameterization to Specify fixed input, reverse transfer, and output capacitance.

Gate-source capacitance with the drain shorted to the source, tabulated with drain-source voltage.

Dependencies

To enable this parameter, in the Capacitance setting, set Parameterization to Specify tabulated input, reverse transfer, and output capacitance.

Drain-gate capacitance with the source connected to ground, also known as the Miller capacitance.

Dependencies

To enable this parameter, in the Capacitance setting, set Parameterization to Specify fixed input, reverse transfer, and output capacitance.

Drain-gate capacitance with the source connected to ground, also known as the Miller capacitance, tabulated with drain-source voltage.

Dependencies

To enable this parameter, in the Capacitance setting, set Parameterization to Specify tabulated input, reverse transfer, and output capacitance.

Drain-source capacitance with the gate and source shorted.

Dependencies

To enable this parameter, in the Capacitance setting, set Parameterization to Specify fixed input, reverse transfer, and output capacitance.

Drain-source capacitance with the gate and source shorted, tabulated with drain-source voltage.

Dependencies

To enable this parameter, in the Capacitance setting, set Parameterization to Specify tabulated input, reverse transfer, and output capacitance.

Capacitance placed between the gate and the source.

Dependencies

To enable this parameter, in the Capacitance setting, set Parameterization to Specify fixed gate-source, gate-drain, and drain-source capacitance.

Capacitance placed between the gate and the source, tabulated with gate-source voltage and drain-source voltage.

Dependencies

To enable this parameter, in the Capacitance setting, set Parameterization to Specify tabulated gate-source, gate-drain, and drain-source capacitance.

Capacitance placed between the gate and the drain.

Dependencies

To enable this parameter, in the Capacitance setting, set Parameterization to Specify fixed gate-source, gate-drain, and drain-source capacitance.

Capacitance placed between the gate and the drain, tabulated with gate-source voltage and drain-source voltage.

Dependencies

To enable this parameter, in the Capacitance setting, set Parameterization to Specify tabulated gate-source, gate-drain, and drain-source capacitance.

Capacitance placed between the gate and the bulk.

Dependencies

To enable this parameter, in the Capacitance setting, set Parameterization to Specify fixed gate-source, gate-drain, and drain-source capacitance and Gate-bulk and gate-source charge-voltage linearity to Separate gate-bulk and gate-source capacitance.

Capacitance placed between the gate and the bulk, tabulated with gate-source voltage and drain-source voltage.

Dependencies

To enable this parameter, in the Capacitance setting, set Parameterization to Specify tabulated gate-source, gate-drain, and drain-source capacitance and Gate-bulk and gate-source charge-voltage linearity to Separate gate-bulk and gate-source capacitance.

Gate-source voltages corresponding to the tabulated capacitance values.

If this value is a scalar, then Gate-source junction capacitance, Cgs(Vgs,Vds) and Gate-drain junction capacitance, Cgd(Vgs,Vds) are vectors of scalars. If this value is a vector, then Gate-source junction capacitance, Cgs(Vgs,Vds) and Gate-drain junction capacitance, Cgd(Vgs,Vds) are matrices of scalars.

Dependencies

To enable this parameter, in the Capacitance setting, set Parameterization to Specify tabulated gate-source, gate-drain, and drain-source capacitance.

Capacitance placed between the drain and the source.

Dependencies

To enable this parameter, in the Capacitance setting, set Parameterization to Specify fixed gate-source, gate-drain, and drain-source capacitance.

Capacitance placed between the drain and the source, tabulated with the drain-source voltage.

Dependencies

To enable this parameter, in the Capacitance setting, set Parameterization to Specify tabulated gate-source, gate-drain, and drain-source capacitance.

Drain-source voltages corresponding to the tabulated capacitance values.

Dependencies

To enable this parameter, in the Capacitance setting, set Parameterization to Specify tabulated input, reverse transfer, and output capacitance or to Specify tabulated gate-source, gate-drain, and drain-source capacitance.

For tabulated capacitance models, this parameter controls the voltage dependence of the Reverse transfer capacitance, Crss or the Gate-drain junction capacitance parameter (depending on the selected parameterization option). These capacitances are a function of the drain-gate voltage. The block calculates drain-gate voltages by subtracting this gate-source voltage value from the values specified for the Corresponding drain-source voltages parameter.

Dependencies

To enable this parameter, in the Capacitance setting, set Parameterization to Specify tabulated input, reverse transfer, and output capacitance.

The two fixed capacitance options let you model gate junction capacitance as a fixed gate-source capacitance CGS and either a fixed or a nonlinear gate-drain capacitance CGD. Select whether the gate-drain capacitance is fixed or nonlinear:

  • Gate-drain capacitance is constant — The capacitance value is constant and defined according to the selected parameterization option, either directly or derived from a datasheet.

  • Gate-drain charge function is nonlinear — The gate-drain charge relationship is defined according to the piecewise-nonlinear function described in Charge Model for Threshold-Based Modeling Option. Two additional parameters appear to let you define the gate-drain charge function.

Dependencies

To enable this parameter, in the Capacitance setting, set Parameterization to Specify fixed input, reverse transfer and output capacitance or to Specify fixed gate-source, gate-drain and drain-source capacitance.

Gate-drain capacitance when the drain-gate voltage is less than the Drain-gate voltage at which oxide capacitance becomes active parameter value.

Dependencies

To enable this parameter, set Gate-drain charge-voltage linearity to Gate-drain charge function is nonlinear.

Drain-gate voltage at which the drain-gate capacitance switches between off-state (CGD) and on-state (Cox) capacitance values.

Dependencies

To enable this parameter, set Gate-drain charge-voltage linearity to Gate-drain charge function is nonlinear.

Gate-bulk and gate-source charge-voltage linearity.

Dependencies

To enable this parameter, in the Main setting, set Number of terminals to Four.

To enable the Separate gate-bulk and gate-source capacitance option, in the Capacitance setting, set Parameterization to Specify fixed gate-source, gate-drain, and drain-source capacitance or Specify tabulated gate-source, gate-drain, and drain-source capacitance

Channel Capacitances

To enable this setting, set Modeling option to Surface-potential-based or Surface-potential-based with thermal.

The parallel plate gate-channel capacitance.

The fixed, linear capacitance associated with the overlap of the gate electrode with the source well.

The fixed, linear capacitance associated with the overlap of the gate electrode with the drain well.

Body Diode

Whether to model the body diode.

Whether to tabulate the current as a function of temperature and voltage or the voltage as a function of temperature and current.

Dependencies

To enable this parameter, set Model body diode to Tabulated I-V curve.

The current designated by the Is symbol in the body-diode equations. The default value for threshold-based modeling option is 0 A. The default value for surface-potential-based modeling option is 5.2e-13 A.

To enable conduction through the body diode, for applications where the MOSFET current changes sign during the simulation, such as when the MOSFET is driving an inductive load, set this parameter to a non-zero value.

For applications where the MOSFET current never changes sign, such as in a small-signal amplifier, set this parameter to 0 to improve simulation speed.

Dependencies

To enable this parameter, set Model body diode to Exponential.

The built-in voltage of the diode, designated by the Vbi symbol in the body-diode equations. Built-in voltage has an impact only on the junction capacitance equation. It does not affect the conduction current.

Dependencies

To enable this parameter, set Model body diode to Exponential.

The factor designated by the n symbol in the body-diode equations.

Dependencies

To enable this parameter, set Model body diode to Exponential.

The capacitance between the drain and bulk contacts at zero-bias due to the body diode alone. It is designated by the Cj0 symbol in the body-diode equations. The default value for threshold-based modeling option is 0 pF. The default value for surface-potential-based modeling option is 480 pF.

Dependencies

To enable this parameter, set Model body diode to Exponential.

The time designated by the τ symbol in the body-diode equations.

When the Reverse saturation current and Transit time parameters are both non-zero, this block includes the reverse recovery inside the body diode model.

Dependencies

To enable this parameter, set Model body diode to Exponential.

Temperature at which the block parameters are measured.

Dependencies

To enable this parameter, set Model body diode to Exponential and, in the Main setting, set Parameterization to either Lookup table (2-D, temperature independent) or Lookup table (3-D, temperature dependent)

Tabulated values of the minimum voltage that needs to be applied for the diode to become forward-biased.

Dependencies

To enable this parameter,

  • In the Main setting, set Parameterization to Specify from a datasheet, Specify from equation parameters directly, or Lookup table (2-D, temperature independent).

  • In the Body diode setting, set:

    • Model body diode to Tabulated I-V curve.

      Table type to Table in Vf(If) form.

Tabulated values of the forward currents.

Dependencies

To enable this parameter, in the Body diode setting, set Model body diode to Tabulated I-V curve and Table type to Table in Vf(If) form or Table in Vf(Tj,If) form.

Tabulated values of the forward current, as a function of the forward voltages.

Dependencies

To enable this parameter,

  • In the Main setting, set Parameterization to Specify from a datasheet, Specify from equation parameters directly, or Lookup table (2-D, temperature independent).

  • In the Body diode setting, set:

    • Model body diode to Tabulated I-V curve.

      Table type to Table in If(Vf) form.

Tabulated values of the forward voltages.

Dependencies

To enable this parameter, in the Body diode setting, set Model body diode to Tabulated I-V curve and Table type to Table in If(Vf) form or Table in If(Tj,Vf) form.

Vector of junction temperatures.

Dependencies

To enable this parameter, set Model body diode to Tabulated I-V curve and, in the Main setting, set Parameterization to Lookup table (3-D, temperature dependent).

Tabulated values of the forward current, as a function of the forward voltages and junction temperatures.

Dependencies

To enable this parameter,

  • In the Main setting, set Parameterization to Lookup table (3-D, temperature dependent).

  • In the Body diode setting, set:

    • Model body diode to Tabulated I-V curve.

      Table type to Table in If(Tj,Vf) form.

Tabulated values of the forward voltage, as a function of the forward currents and junction temperatures.

Dependencies

To enable this parameter,

  • In the Main setting, set Parameterization to Lookup table (3-D, temperature dependent).

  • In the Body diode setting, set:

    • Model body diode to Tabulated I-V curve.

      Table type to Table in Vf(Tj,If) form.

Temperature Dependence (Threshold-Based Modeling Option)

This configuration of the Temperature Dependence setting corresponds to the threshold-based block modeling option, which is the default. If you are using the surface-potential-based modeling option of the block, see Temperature Dependence (Surface-Potential-Based Modeling Option)

Select one of the following methods for temperature dependence parameterization:

  • None — Simulate at parameter measurement temperature — Temperature dependence is not modeled. This is the default method.

  • Model temperature dependence — Model temperature-dependent effects. Provide a value for simulation temperature, Ts, a value for BEX, and a value for the measurement temperature Tm1 (using the Measurement temperature parameter on the Main setting). You also have to provide a value for α using one of two methods, depending on the value of the Parameterization parameter on the Main setting. If you parameterize the block from a datasheet, you have to provide RDS(on) at a second measurement temperature, and the block will calculate α based on that. If you parameterize by specifying equation parameters, you have to provide the value for α directly.

The ratio of the drain-source voltage to the drain current for specified values of drain current and gate-source voltage at second measurement temperature. It must be quoted for the same working point (drain current and gate-source voltage) as the Drain-source on resistance, R_DS(on) parameter on the Main setting.

Dependencies

This parameter is visible only when you select Specify from a datasheet for the Parameterization parameter on the Main setting.

Second temperature Tm2 at which Drain-source on resistance, R_DS(on), at second measurement temperature is measured.

Dependencies

This parameter is visible only when you select Specify from a datasheet for the Parameterization parameter on the Main setting.

The rate of change of gate threshold voltage with temperature.

Dependencies

This parameter is visible only when you select Specify using equation parameters directly for the Parameterization parameteron the Main setting.

Mobility temperature coefficient value. You can use the default value for most MOSFETs. See the Assumptions and Limitations section for additional considerations.

The reverse saturation current for the body diode is assumed to be proportional to the square of the intrinsic carrier concentration, ni = NC exp(–EG/2kBT). NC is the temperature-dependent effective density of states and EG is the temperature-dependent bandgap for the semiconductor material. To avoid introducing another temperature-scaling parameter, the block neglects the temperature dependence of the bandgap and uses the bandgap of silicon at 300K (1.12eV) for all device types. Therefore, the temperature-scaled reverse saturation current is given by

Is=Is,m1(TsTm1)ηIsexp(EGkB(1Tm11Ts)).

Is,m1 is the value of the Reverse saturation current parameter from the Body Diode setting, kB is Boltzmann’s constant (8.617x10-5eV/K), and ηIs is the Body diode reverse saturation current temperature exponent. The default value is 3, because NC for silicon is roughly proportional to T3/2. You can remedy the effect of neglecting the temperature-dependence of the bandgap by a pragmatic choice of ηIs.

Temperature Ts at which the device is simulated.

Temperature Dependence (Surface-Potential-Based Modeling Option)

This configuration of the Temperature Dependence setting corresponds to the surface-potential-based block modeling option. If you are using the threshold-based modeling option of the block, see Temperature Dependence (Threshold-Based Modeling Option)

Select one of the following methods for temperature dependence parameterization:

  • None — Simulate at parameter measurement temperature — Temperature dependence is not modeled.

  • Model temperature dependence — Model temperature-dependent effects. Provide a value for the device simulation temperature, Ts, and the temperature-scaling coefficients for other block parameters.

The MOSFET gain, β, is assumed to scale exponentially with temperature, β = β m1(Tm1/Ts)^ηβ. βm1 is the value of the Gain parameter from the Main setting and ηβ is the Gain temperature exponent.

The flatband voltage, VFB, is assumed to scale linearly with temperature, VFB = VFBm1 + (TsTm1)ST,VFB. VFBm1 is the value of the Flatband voltage parameter from the Main setting and ST,VFB is the Flatband voltage temperature coefficient.

The surface potential at strong inversion, 2ϕB, is assumed to scale linearly with temperature, B = 2ϕBm1 + (TsTm1)ST,ϕB. 2ϕBm1 is the value of the Surface potential at strong inversion parameter from the Main setting and ST,ϕB is the Surface potential at strong inversion temperature coefficient.

The velocity saturation, θsat, is assumed to scale exponentially with temperature, θsat = θsat,m1 (Tm1/Ts)^ηθ. θsat,m1 is the value of the Velocity saturation factor parameter from the Main setting and ηθ is the Velocity saturation temperature exponent.

This parameter leads to a temperature-dependent reduction in the MOSFET transconductance at high gate voltage. The surface roughness scattering, θsr, is assumed to scale exponentially with temperature, θsr = θsr,m1 (Tm1/Ts)^ηsr. θsr,m1 is the value of the Surface roughness scattering factor parameter from the Main setting and ηsr is the Surface roughness scattering temperature exponent.

The series resistances are assumed to correspond to semiconductor resistances. Therefore, they decrease exponentially with increasing temperature. Ri = Ri,m1 (Tm1/Ts)^ηR, where i is S, D, or G, for the source, drain, or gate series resistance, respectively. Ri,m1 is the value of the corresponding series resistance parameter from the Ohmic Resistance setting and ηR is the Resistance temperature exponent.

The reverse saturation current for the body diode is assumed to be proportional to the square of the intrinsic carrier concentration, ni = NC exp(–EG/2kBT). NC is the temperature-dependent effective density of states and EG is the temperature-dependent bandgap for the semiconductor material. To avoid introducing another temperature-scaling parameter, the block neglects the temperature dependence of the bandgap and uses the bandgap of silicon at 300K (1.12eV) for all device types. Therefore, the temperature-scaled reverse saturation current is given by

Is=Is,m1(TsTm1)ηIsexp(EGkB(1Tm11Ts)).

Is,m1 is the value of the Reverse saturation current parameter from the Body Diode setting, kB is Boltzmann’s constant (8.617x10-5eV/K), and ηIs is the Body diode reverse saturation current temperature exponent. The default value is 3, because NC for silicon is roughly proportional to T3/2. You can remedy the effect of neglecting the temperature-dependence of the bandgap by a pragmatic choice of ηIs.

Temperature Ts at which the device is simulate.

Faults

Whether to enable faults in MOSFET.

Whether to trigger faults on temporal or behavioral conditions. Set this parameter to:

  • Temporal — Trigger fault at a specific time.

  • Behavioral — Trigger fault when a current limit or a voltage limit are exceeded for longer than a specific time interval.

Simulation time at which you want the block to enter the faulted state.

Dependencies

To enable this parameter, set Enable faults to On and Fault trigger to Temporal.

Maximum permissible gate-source voltage value, above which a fault might be triggered.

Dependencies

To enable this parameter, set Enable faults to On and Fault trigger to Behavioral.

Maximum permissible drain-source voltage value, above which a fault might be triggered.

Dependencies

To enable this parameter, set Enable faults to On and Fault trigger to Behavioral.

Maximum permissible drain-bulk voltage value, above which a fault might be triggered.

Dependencies

To enable this parameter, set:

  • In the Main setting, Number of terminals to Four.

  • Enable faults to On.

  • Fault trigger to Behavioral.

Maximum permissible drain-source current value. If the current exceeds this value for longer than the value of the Time to fail when exceeding drain-source current parameter, then the block enters the faulted state.

Dependencies

To enable this parameter, set Enable faults to On and Fault trigger to Behavioral.

Amount of time that the drain-source current must continuously exceed the maximum permissible drain-source current before a behavioral fault is triggered.

Dependencies

To enable this parameter, set Enable faults to On and Fault trigger to Behavioral.

Maximum permissible body diode current value. If the current exceeds this value for longer than the value of the Time to fail when exceeding body diode current parameter, then the block enters the faulted state.

Dependencies

To enable this parameter, set Model body diode to either Exponential or Tabulated I-V curve, Enable faults to On, and Fault trigger to Behavioral.

Amount of time that the body diode current must continuously exceed the maximum permissible body diode current before a behavioral fault is triggered.

Dependencies

To enable this parameter, set Model body diode to either Exponential or Tabulated I-V curve, Enable faults to On, and Fault trigger to Behavioral.

Maximum amount of diode recovery per second.

Dependencies

To enable this parameter, set Model body diode to either Exponential or Tabulated I-V curve, Enable faults to On, and Fault trigger to Behavioral.

Maximum permissible temperature value. If the temperature exceeds this value for longer than the value of the Time to fail when exceeding temperature parameter, then the block enters the faulted state.

Dependencies

To enable this parameter, set Modeling option to Threshold-based with thermal, Enable faults to On, and Fault trigger to Behavioral.

Amount of time that the temperature must continuously exceed the maximum permissible temperature before a behavioral fault is triggered.

Dependencies

To enable this parameter, set Modeling option to Threshold-based with thermal, Enable faults to On, and Fault trigger to Behavioral.

Time constant for transitioning to faulted state.

Dependencies

To enable this parameter, set Enable faults to On.

Type of failure. You can set this parameter to:

  • Open circuit — Failure due to metallization burnout.

  • Drain-source short — Failure due to avalanche breakout on drain-source channel.

  • Drain-bulk short or source-bulk short — Failure due to avalanche breakout on drain-bulk or source-bulk channels.

  • Gate oxide short — Failure of the gate oxide dielectric layer.

  • Parameter shift — Failure due to aging.

Dependencies

To enable this parameter, set Enable faults to On.

To enable the Drain-source short option, in the Main setting, set Number of terminals to Three.

To enable the Drain-bulk short or source-bulk short option, in the Main setting, set Number of terminals to Four.

Series gate resistance in faulted state.

Dependencies

To enable this parameter, set Enable faults to On and Failure mode to Open circuit.

Series drain resistance in faulted state.

Dependencies

To enable this parameter, set Enable faults to On and Failure mode to Open circuit.

Series source resistance in faulted state.

Dependencies

To enable this parameter, set Enable faults to On and Failure mode to Open circuit.

Series source resistance in faulted state.

Dependencies

To enable this parameter, set:

  • In the Main setting, Number of terminals to Four.

  • Enable faults to On.

  • Failure mode to Open circuit.

Parallel drain-source conductance in faulted state.

Dependencies

To enable this parameter, set:

  • In the Main setting, Number of terminals to Three.

  • Enable faults to On.

  • Failure mode to Drain-source short.

Parallel drain-bulk conductance in faulted state.

Dependencies

To enable this parameter, set:

  • In the Main setting, Number of terminals to Four.

  • Enable faults to On.

  • Failure mode to Drain-bulk short or source-bulk short.

Parallel source-bulk conductance in faulted state.

Dependencies

To enable this parameter, set:

  • In the Main setting, Number of terminals to Four.

  • Enable faults to On.

  • Failure mode to Drain-bulk short or source-bulk short.

Location of the fault node, as a percentage of the total channel length from the source.

Dependencies

To enable this parameter, set Enable faults to On and Failure mode to Gate oxide short.

Gate oxide short conductance.

Dependencies

To enable this parameter, set Enable faults to On and Failure mode to Gate oxide short.

Whether to model the gate oxide short diode.

Dependencies

To enable this parameter, set Enable faults to On and Failure mode to Gate oxide short.

Reverse saturation current of the gate oxide short diode.

Dependencies

To enable this parameter, set:

  • Enable faults to On.

  • Failure mode to Gate oxide short.

  • Model gate oxide short diode to Yes.

Built-in voltage of the gate oxide short diode.

Dependencies

To enable this parameter, set:

  • Enable faults to On.

  • Failure mode to Gate oxide short.

  • Model gate oxide short diode to Yes.

Ideality factor of the gate oxide short diode.

Dependencies

To enable this parameter, set:

  • Enable faults to On.

  • Failure mode to Gate oxide short.

  • Model gate oxide short diode to Yes.

Zero-bias junction capacitance of the gate oxide short diode.

Dependencies

To enable this parameter, set:

  • Enable faults to On.

  • Failure mode to Gate oxide short.

  • Model gate oxide short diode to Yes.

Transit time of the gate oxide short diode.

Dependencies

To enable this parameter, set:

  • Enable faults to On.

  • Failure mode to Gate oxide short.

  • Model gate oxide short diode to Yes.

Shifted gain as percentage of unshifted.

Dependencies

To enable this parameter, set:

  • In the Main setting, Parameterization to Specify from a datasheet or Specify using equation parameters directly.

  • Enable faults to On.

  • Failure mode to Parameter shift.

Shift value of Threshold voltage.

Dependencies

To enable this parameter, set:

  • In the Main setting, Parameterization to Specify from a datasheet or Specify using equation parameters directly.

  • Enable faults to On.

  • Failure mode to Parameter shift.

Channel modulation in faulted state.

Dependencies

To enable this parameter, set:

  • In the Main setting, Parameterization to Specify from a datasheet or Specify using equation parameters directly.

  • Enable faults to On.

  • Failure mode to Parameter shift.

Shifted body factor as percentage of unshifted.

Dependencies

To enable this parameter, set:

  • In the Main setting, Number of terminals to Four.

  • In the Main setting, Parameterization to Specify from a datasheet or Specify using equation parameters directly.

  • Enable faults to On.

  • Failure mode to Parameter shift.

Shift value of surface potential.

Dependencies

To enable this parameter, set:

  • In the Main setting, Number of terminals to Four.

  • In the Main setting, Parameterization to Specify from a datasheet or Specify using equation parameters directly.

  • Enable faults to On.

  • Failure mode to Parameter shift.

Transistor source resistance in faulted state.

Dependencies

To enable this parameter, set:

  • In the Main setting, Parameterization to Specify from a datasheet or Specify using equation parameters directly.

  • Enable faults to On.

  • Failure mode to Parameter shift.

Transistor drain resistance in faulted state.

Dependencies

To enable this parameter, set:

  • In the Main setting, Parameterization to Specify from a datasheet or Specify using equation parameters directly.

  • Enable faults to On.

  • Failure mode to Parameter shift.

Transistor body resistance in faulted state.

Dependencies

To enable this parameter, set:

  • In the Main setting, Number of terminals to Four.

  • In the Main setting, Parameterization to Specify from a datasheet or Specify using equation parameters directly.

  • Enable faults to On.

  • Failure mode to Parameter shift.

Gate-source voltages in faulted state.

Dependencies

To enable this parameter, set:

  • In the Main setting, Parameterization to Lookup table (2-D, temperature independent) or Lookup table (3-D, temperature dependent).

  • Enable faults to On.

  • Failure mode to Parameter shift.

Drain-source voltages in faulted state.

Dependencies

To enable this parameter, set:

  • In the Main setting, Parameterization to Lookup table (2-D, temperature independent) or Lookup table (3-D, temperature dependent).

  • Enable faults to On.

  • Failure mode to Parameter shift.

Bulk-source voltages in faulted state.

Dependencies

To enable this parameter, set:

  • In the Main setting, Number of terminals to Four.

  • In the Main setting, Parameterization to Lookup table (2-D, temperature independent) or Lookup table (3-D, temperature dependent).

  • Enable faults to On.

  • Failure mode to Parameter shift.

Tabulated gate-source threshold voltage in faulted state.

Dependencies

To enable this parameter, set:

  • In the Main setting, Number of terminals to Four.

  • In the Main setting, Parameterization to Lookup table (2-D, temperature independent).

  • Enable faults to On.

  • Failure mode to Parameter shift.

Gate-source threshold voltage in faulted state, tabulated on bulk-source voltage and temperature.

Dependencies

To enable this parameter, set:

  • In the Main setting, Number of terminals to Four.

  • In the Main setting, Parameterization to Lookup table (3-D, temperature independent).

  • Enable faults to On.

  • Failure mode to Parameter shift.

Tabulated drain-source currents in faulted state.

Dependencies

To enable this parameter, set:

  • In the Main setting, Number of terminals to Three.

  • In the Main setting, Parameterization to Lookup table (2-D, temperature independent).

  • Enable faults to On.

  • Failure mode to Parameter shift.

Drain-source currents in faulted state, tabulated on gate-source voltage, drain-source voltage, and temperature.

Dependencies

To enable this parameter, set:

  • In the Main setting, Number of terminals to Three.

  • In the Main setting, Parameterization to Lookup table (3-D, temperature independent).

  • Enable faults to On.

  • Failure mode to Parameter shift.

Tabulated drain-source currents in faulted state, when the bulk-source voltage is zero.

Dependencies

To enable this parameter, set:

  • In the Main setting, Number of terminals to Four.

  • In the Main setting, Parameterization to Lookup table (2-D, temperature independent).

  • Enable faults to On.

  • Failure mode to Parameter shift.

Tabulated drain-source currents in faulted state, when the bulk-source voltage is zero, tabulated on gate-source voltage, drain-source voltage, and temperature.

Dependencies

To enable this parameter, set:

  • In the Main setting, Number of terminals to Four.

  • In the Main setting, Parameterization to Lookup table (3-D, temperature independent).

  • Enable faults to On.

  • Failure mode to Parameter shift.

Gate-source capacitance in faulted state as percentage of unfaulted.

Dependencies

To enable this parameter, meet one of these sets of conditions:

Condition Set One

  • In the Capacitance setting, set Parameterization to Specify fixed input, reverse transfer, and output capacitance or Specify fixed gate-source, gate-drain, and drain-source capacitance .

  • In the Faults setting, set Enable faults to On.

Condition Set Two

  • In the Capacitance setting, set Parameterization to Specify tabulated input, reverse transfer, and output capacitance or Specify tabulated gate-source, gate-drain, and drain-source capacitance.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Open circuit, Drain-source short, Drain-bulk short or source-bulk short, or Gate oxide short.

Gate-drain capacitance in faulted state as percentage of unfaulted.

Dependencies

To enable this parameter, meet one of these sets of conditions:

Condition Set One

  • In the Capacitance setting, set Parameterization to Specify fixed input, reverse transfer, and output capacitance or Specify fixed gate-source, gate-drain, and drain-source capacitance .

  • In the Faults setting, set Enable faults to On.

Condition Set Two

  • In the Capacitance setting, set Parameterization to Specify tabulated input, reverse transfer, and output capacitance or Specify tabulated gate-source, gate-drain, and drain-source capacitance.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Open circuit, Drain-source short, Drain-bulk short or source-bulk short, or Gate oxide short.

Gate-bulk capacitance in faulted state as percentage of unfaulted.

Dependencies

To enable this parameter, meet one of these sets of conditions:

Condition Set One

  • In the Main setting, Number of terminals to Four.

  • In the Capacitance setting, set:

    • Parameterization to Specify fixed gate-source, gate-drain, and drain-source capacitance.

    • Gate-bulk and gate-source charge-voltage linearity to Separate gate-bulk and gate-source capacitance.

  • In the Faults setting, set Enable faults to On.

Condition Set Two

  • In the Main setting, Number of terminals to Four.

  • In the Capacitance setting, set:

    • Parameterization to Specify tabulated gate-source, gate-drain, and drain-source capacitance.

    • Gate-bulk and gate-source charge-voltage linearity to Separate gate-bulk and gate-source capacitance.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Open circuit, Drain-bulk short or source-bulk short, or Gate oxide short.

Drain-source capacitance in faulted state as percentage of unfaulted.

Dependencies

To enable this parameter, meet one of these sets of conditions:

Condition Set One

  • In the Capacitance setting, set Parameterization to Specify fixed input, reverse transfer, and output capacitance or Specify fixed gate-source, gate-drain, and drain-source capacitance .

  • In the Faults setting, set Enable faults to On.

Condition Set Two

  • In the Capacitance setting, set Parameterization to Specify tabulated input, reverse transfer, and output capacitance or Specify tabulated gate-source, gate-drain, and drain-source capacitance.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Open circuit, Drain-source short, Drain-bulk short or source-bulk short, or Gate oxide short.

Gate-drain oxide capacitance in faulted state as percentage of unfaulted.

Dependencies

To enable this parameter,

  • In the Capacitance setting, set:

    • Parameterization to Specify fixed input, reverse transfer, and output capacitance or Specify fixed gate-source, gate-drain, and drain-source capacitance.

    • Gate-drain charge-voltage linearity to Gate-drain charge function is non linear.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Parameter shift.

Drain-gate voltage in faulted state at which oxide capacitance becomes active.

Dependencies

To enable this parameter,

  • In the Capacitance setting, set:

    • Parameterization to Specify fixed input, reverse transfer, and output capacitance or Specify fixed gate-source, gate-drain, and drain-source capacitance.

    • Gate-drain charge-voltage linearity to Gate-drain charge function is non linear.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Parameter shift.

Input capacitance in faulted state.

Dependencies

To enable this parameter,

  • In the Capacitance setting, set Parameterization to Specify tabulated input, reverse transfer, and output capacitance.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Parameter shift.

Reverse transfer capacitance in faulted state.

Dependencies

To enable this parameter,

  • In the Capacitance setting, set Parameterization to Specify tabulated input, reverse transfer, and output capacitance.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Parameter shift.

Output capacitance in faulted state.

Dependencies

To enable this parameter,

  • In the Capacitance setting, set Parameterization to Specify tabulated input, reverse transfer, and output capacitance.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Parameter shift.

Corresponding drain-source voltages in faulted state.

Dependencies

To enable this parameter,

  • In the Capacitance setting, set Parameterization to Specify tabulated input, reverse transfer, and output capacitance or Specify tabulated gate-source, gate-drain, and drain-source capacitance.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Parameter shift.

Gate-source voltages for tabulated capacitances, in faulted state.

Dependencies

To enable this parameter, meet one of these sets of conditions:

Condition Set One

  • In the Capacitance setting, set Parameterization to Specify tabulated input, reverse transfer, and output capacitance.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Parameter shift.

Condition Set Two

  • In the Main setting, Number of terminals to Four.

  • In the Capacitance setting, set:

    • Parameterization to Specify tabulated gate-source, gate-drain, and drain-source capacitance.

    • Gate-bulk and gate-source charge-voltage linearity to Gate-bulk and gate-source capacitance change instantly or Gate-bulk and gate-source capacitance change gradually.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Parameter shift.

Gate-source junction capacitance in faulted state, tabulated with gate-source voltage and drain-source voltage.

Dependencies

To enable this parameter,

  • In the Capacitance setting, set Parameterization to Specify tabulated gate-source, gate-drain, and drain-source capacitance.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Parameter shift.

Gate-drain junction capacitance in faulted state, tabulated with gate-source voltage and drain-source voltage.

Dependencies

To enable this parameter,

  • In the Capacitance setting, set Parameterization to Specify tabulated gate-source, gate-drain, and drain-source capacitance.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Parameter shift.

Gate-bulk junction capacitance in faulted state, tabulated with gate-source voltage and drain-source voltage.

Dependencies

To enable this parameter,

  • In the Main setting, set Number of terminals to Four.

  • In the Capacitance setting, set:

    • Parameterization to Specify tabulated gate-source, gate-drain, and drain-source capacitance.

    • Gate-bulk and gate-source charge-voltage linearity to Separate gate-bulk and gate-source capacitance.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Parameter shift.

Corresponding gate-source voltages in faulted state.

Dependencies

To enable this parameter,

  • In the Capacitance setting, set:

    • Parameterization to Specify tabulated gate-source, gate-drain, and drain-source capacitance.

    • Gate-bulk and gate-source charge-voltage linearity to Separate gate-bulk and gate-source capacitance.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Parameter shift.

Reverse saturation current of the diode in faulted state.

Dependencies

To enable this parameter,

  • In the Body Diode setting, set Model body diode to Exponential.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Parameter shift.

Built-in voltage of the diode in faulted state.

Dependencies

To enable this parameter,

  • In the Body Diode setting, set Model body diode to Exponential.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Parameter shift.

Ideality factor of the diode in faulted state.

Dependencies

To enable this parameter,

  • In the Body Diode setting, set Model body diode to Exponential.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Parameter shift.

Faulted diode zero-bias junction capacitance as percentage of unfaulted.

Dependencies

To enable this parameter,

  • In the Body Diode setting, set Model body diode to Exponential.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Parameter shift.

Transit time of the diode in faulted state.

Dependencies

To enable this parameter,

  • In the Body Diode setting, set Model body diode to Exponential.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Parameter shift.

Forward currents of the diode in faulted state, tabulated with the forward voltages.

Dependencies

To enable this parameter,

  • In the Main setting, set Parameterization to Specify from a datasheet, Specify using equation parameters directly, or Lookup table (2-D, temperature independent).

  • In the Body Diode setting, set:

    • Model body diode to Tabulated I-V curve.

    • Table type to Table in If(Vf) form.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Parameter shift.

Forward voltages of the diode in faulted state.

Dependencies

To enable this parameter,

  • In the Body Diode setting, set:

    • Model body diode to Tabulated I-V curve.

    • Table type to Table in If(Vf) form or Table in If(Tj,Vf) form

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Parameter shift.

Forward voltages of the diode in faulted state, tabulated with the forward currents.

Dependencies

To enable this parameter,

  • In the Main setting, set Parameterization to Specify from a datasheet, Specify using equation parameters directly, or Lookup table (2-D, temperature independent).

  • In the Body Diode setting, set:

    • Model body diode to Tabulated I-V curve.

    • Table type to Table in Vf(If) form.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Parameter shift.

Forward currents of the diode in faulted state.

Dependencies

To enable this parameter,

  • In the Body Diode setting, set:

    • Model body diode to Tabulated I-V curve.

    • Table type to Table in Vf(If) form and Table in Vf(Tj,If) form.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Parameter shift.

Forward currents of the diode in faulted state, tabulated with the forward voltages and junction temperatures.

Dependencies

To enable this parameter,

  • In the Main setting, set Parameterization to Lookup table (3-D, temperature dependent).

  • In the Body Diode setting, set:

    • Model body diode to Tabulated I-V curve.

    • Table type to Table in If(Tj,Vf) form.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Parameter shift.

Forward voltages of the diode in faulted state, tabulated with the forward currents and junction temperatures.

Dependencies

To enable this parameter,

  • In the Main setting, set Parameterization to Lookup table (3-D, temperature dependent).

  • In the Body Diode setting, set:

    • Model body diode to Tabulated I-V curve.

    • Table type to Table in Vf(Tj,If) form.

  • In the Faults setting, set:

    • Enable faults to On.

    • Failure mode to Parameter shift.

References

[1] Shichman, H. and D. A. Hodges. “Modeling and simulation of insulated-gate field-effect transistor switching circuits.” IEEE J. Solid State Circuits. SC-3, 1968.

[2] Van Langevelde, R., A. J. Scholten, and D. B .M. Klaassen. "Physical Background of MOS Model 11. Level 1101." Nat.Lab. Unclassified Report 2003/00239. April 2003.

[3] Oh, S-Y., D. E. Ward, and R. W. Dutton. “Transient analysis of MOS transistors.” IEEE J. Solid State Circuits. SC-15, pp. 636-643, 1980.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2008a