MOSFET (Ideal, Switching)

Ideal N-channel MOSFET for switching applications

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Libraries:
Simscape / Electrical / Semiconductors & Converters

Description

The MOSFET (Ideal, Switching) block models the ideal switching behavior of an n-channel metal-oxide-semiconductor field-effect transistor (MOSFET).

The switching characteristic of an n-channel MOSFET is such that if the gate-source voltage exceeds the specified threshold voltage, the MOSFET is in the on state. Otherwise, the device is in the off state. This figure shows a typical i-v characteristic:

To define the I-V characteristic of the MOSFET, set the On-state behavior and switching losses parameter to either Specify constant values or Tabulate. The Tabulate option is available only if you expose the thermal port of the block.

In the on state, the drain-source path behaves like a linear resistor with resistance, R_{ds_on}. However, if you expose the thermal port of the block and parameterize the device using tabulated I-V data, the tabulated resistance is a function of the temperature and current.

In the off state, the drain-source path behaves like a linear resistor with low off-state conductance, G_off.

Then, the defining Simscape™ equations for the block are:

    if G > Vth       v == i*Rds_on;     else       v == i/Goff;     end 

where:

• G depends on the value of the Gate-control port parameter.

  • If you set the Gate-control port parameter to PS, you control the gate terminal through a physical signal. G is the value at the input port G.

  • If you set the Gate-control port parameter to Electrical, you control the gate terminal through an electrical signal. G is equal to:

        if v >= 0        G = G.v - S.v;     else       G = G.v - D.v;     end 

    where G.v is the gate voltage, S.v is the source voltage, and D.v is the drain voltage.

• Vth is the threshold voltage.

• v is the drain-source voltage.

• i is the drain-source current.

• Rds_on is the on-state resistance.

• Goff is the off-state conductance.

Using the Integral Diode settings, you can include the body diode or an integral protection diode. The integral diode provides a conduction path for reverse current and allows for an increased numerical stability in your model. For example, to provide a path for a high reverse-voltage spike that is generated when a semiconductor device suddenly switches off the voltage supply to an inductive load.

Set the Integral protection diode parameter based on your goal.

Goals		Value to Select	Integral Protection Diode
Do not include protection.		External diode	None
Include protection.	Prioritize simulation speed.	Diode with no dynamics	The Diode block
	Prioritize model fidelity by precisely specifying reverse-mode charge dynamics.	Diode with charge dynamics	The dynamic model of the Diode block

Model Gate Port and Thermal Effects

You can choose between physical or electrical ports to control the gate terminal and expose the thermal port to model the heat that switching events and conduction losses generate. To choose the gate-control port, set the Gate-control port parameter to PS or Electrical. To expose the thermal port, set the Modeling option parameter to No thermal port or Show thermal port.

You can also expose the thermal port HDiode of the integral protection diode by selecting the Separate thermal port for integral diode parameter. If you do not expose the diode thermal port, both the device and the diode share the common thermal port, H. (since R2024b)

For more information about using thermal ports, see Simulating Thermal Effects in Semiconductors.

Thermal Losses

The figure shows an idealized representation of the output voltage, V_out, and the output current, I_out, of the semiconductor device. The interval in this figure includes the entire nth switching cycle, during which the block turns off and then on.

Switching losses are major sources of thermal loss in semiconductors. During each on-off switching transition, the MOSFET parasitics store and then dissipate energy.

Switching losses depend on the off-state voltage and the on-state current. When a switching device turns on, the power losses depend on the initial off-state voltage across the device and the final on-state current when the device is in its fully on state. Similarly, when a switching device turns off, the power losses depend on the initial on-state current through the device and the final off-state voltage across the device in the fully off state.

You can choose when to measure the current and voltage that the block uses to calculate the switch-on and switch-off losses. For most circuits, you can make the measurements during the turn-on or turn-off event:

• The switch-on loss is E_on(I_TurnOn(n),V_TurnOn(n))

• The switch-off loss is E_off(I_TurnOff(n),V_TurnOff(n))

However, you cannot always use these measurements, for example, in these situations:

• You are modeling a capacitance across the switching device. For example, you are modeling the protection diode with capacitance or you are using the Lauritzen charge model. The capacitance causes an overshoot transient in the current at device turn-on, which means that you cannot use the measurement I_TurnOn(n) to calculate the switch-on loss. The block requires the value following the transient. Do not model capacitance across the switching device, because this model mixes an abstracted behavior for the semiconductor switching device with detailed physics for the diode. If you must model capacitance across the switching device, you can use the current measurement at the end of the last on-period, I_TurnOff(n-1). To enable this option, select the Use last on-state current from previous cycle for turn-on loss parameter.

• You are modeling switching device lead inductance. The inductance causes an overshoot transient in the voltage at device turn-off, which means that you cannot use the measurement V_TurnOff(n) to calculate the switch-off loss. The block requires the value following the transient. Do not model switching device lead inductance, because the time constant associated with lead inductance is typically much smaller than the pulse-width modulation (PWM) period. This smaller time constant means that the simulation requires smaller simulation time steps, slowing down the simulation. If you must model switching device lead inductance, use the voltage measurement at the end of the last off-period, V_TurnOn(n). To enable this option, select the Use last off-state voltage from previous cycle for turn-off loss parameter.

Examine the simulation results to check that the losses behave as you expect. To learn how to log and plot simulation data, see the Log and Plot Simulation Data example. This table defines the names of variables in the logged simulation data that are relevant to switching loss calculations.

Voltages and Currents Used to Calculate Switching Losses

Quantity	Variable Name in Logged Simulation Data
VTurnOn	zvOn
ITurnOn	ziOn
VTurnOff	zvOff
ITurnOff	ziOff

This block applies switching losses by stepping up the junction temperature with a value equal to the switching loss divided by the total thermal mass at the junction. You must specify the energy dissipated during a single switch-on and switch-off event. You must also specify the corresponding values of the off-state voltage and on-state current at which you quote the losses. You can parameterize the switching losses, depending on the data you have. Use tabulated data if they are available.

• To specify a scalar value for the switching losses, set the On-state behavior and switching losses parameter to Specify constant values. The Switch-on loss and Switch-off loss parameter values set the sizes of the switching losses. The block scales the losses by the off-state voltage and the on-state current.

• To specify the losses as a function of the junction temperature and on-state current at a fixed off-state voltage, set the On-state behavior and switching losses parameter to Tabulate and clear the Include switching loss tabulation with off-state Vds voltage parameter. The Switch-on loss, Eon(Tj,Ids) and Switch-off, Eoff(Tj,Ids) parameters set the size of the losses. The block scales the losses by the off-state voltage.

• To specify the losses as a function of the junction temperature, on-state current, and off-state voltage, set the On-state behavior and switching losses parameter to Tabulate and select the Include switching loss tabulation with off-state Vds voltage parameter.

Reverse recovery loss can be a significant source of thermal loss in diodes. The diode dissipates energy every time it turns off, from its conducting state to the open-circuit state. To model reverse recovery loss:

• Set Modeling option to Show thermal port.

• Set Integral protection diode to Diode with no dynamics.

If you set the Reverse recovery loss model parameter to Tabulated loss, the value of the Reverse recovery loss table, Erec(Tj, If) parameter specifies the dissipated energy as a function of the junction temperature and the forward current just before the switching event. The off-state voltage linearly scales the losses relative to the Turn-off voltage when measuring recovery loss, Vrec parameter value. The table uses delayed values for the current and voltage. To use a value in the lookup table that is close to the instantaneous value, set the Filter time constant for voltage and current values parameter to a value that is lower than the fastest switching period.

If you set the Reverse recovery loss model parameter to Fixed loss, the value of the Reverse recovery loss parameter specifies the energy dissipated during each turn-off event. If you select the Scale reverse recovery loss with current and voltage parameter, then the block scales this loss value linearly by the on-state current and the off-state voltage. To use scaling values that are close to the instantaneous values, set Filter time constant for voltage and current values to a value that is lower than the fastest switching period.

As an alternative method to model reverse recovery, you can set the Integral protection diode parameter to Diode with charge dynamics. However, this approach requires smaller simulation time steps than using the first approach.

Note

For all ideal switching devices, the logged simulation data reports the thermal losses as lastTurnOffLoss, lastTurnOnLoss, and lastReverseRecoveryLoss. These variables record losses as a pulse with an amplitude equal to the energy loss. If you use a script to sum the total losses over a defined simulation period, you must sum the pulse values at each pulse rising edge. Alternatively, you can extract conduction and switching losses from logged data using the ee_getPowerLossSummary and ee_getPowerLossTimeSeries functions.

You can also access the total accumulated switching losses from the accumulatedSwitchingLosses variable in the logged simulation data. This variable sums all switching losses to date, including reverse recovery losses for the diode.

The power_dissipated variable in the logged simulation data does not include switching losses or reverse recovery losses because the block models these losses as instantaneous events. The power_dissipated variable reports ohmic on-state losses.

If you are using a fixed-step solver, the shortest pulse on or pulse off that supports capture of the switching losses is three time steps long. If the pulse is shorter than three steps, the block does not report switching losses.

If you are operating the MOSFET in the reverse region (negative drain-source currents), the logged simulation data does not report any switch-on or switch-off losses because the parallel diode provides continuous parallel conduction. In the logged simulation data, ziOn reports zero current to implement the zero losses even if the current steps to a negative value.

If you use tabulated data to model the switching losses or reverse recovery losses, check that the temperature, current, and voltage are in the range you specify. If you do not define a realistic thermal model, for example, if the junction mass or the conductance from the junction to the case is too small, the temperature can exceed the range you specify, causing the block to extrapolate the losses to nonphysical values.

Parameterization

The MOSFET (Ideal, Switching) block supports multiple predefined parameterizations.

Use this parameterization data to represent components by specific suppliers. The parameterizations of these MOSFETs match the manufacturer data sheets. To load a predefined parameterization, double-click the MOSFET (Ideal, Switching) block, click the <click to select> hyperlink of the Selected part parameter, and, in the Block Parameterization Manager window, select the part you want to use from the list of available components.

Note

The predefined parameterizations of Simscape components use available data sources for the parameter values. Engineering judgement and simplifying assumptions are used to fill in for missing data. As a result, expect deviations between simulated and actual physical behavior. To ensure accuracy, validate the simulated behavior against experimental data and refine component models as necessary.

For more information about predefined parameterization and a list of the available components, see List of Pre-Parameterized Components.

You can also use the ee_importDeviceParameters function to extract the device parameters from an XML file and import them into the block. The XML file must be on the MATLAB^® path and must use a parameterization format supported by Hitachi.

Variables

To set the priority and initial target values for the block variables before simulation, use the Initial Targets section in the block dialog box or Property Inspector. For more information, see Set Priority and Initial Target for Block Variables.

Use nominal values to specify the expected magnitude of a variable in a model. Using system scaling based on nominal values increases the simulation robustness. Nominal values can come from different sources. One of these sources is the Nominal Values section in the block dialog box or Property Inspector. For more information, see System Scaling by Nominal Values.

Plot Basic I-V Characteristics

Since R2023b

You can plot the basic I-V characteristics of the MOSFET (Ideal, Switching) block without building a complete model. Use the plots to explore the impact of your parameter choices on device characteristics. If you parameterize the block from a datasheet, you can compare your plots to the datasheet to check that you parameterized the block correctly. If you have a complete working model but do not know which manufactured part to use, you can compare your plots to datasheets to help you decide.

To plot the basic characteristics, right-click the block and select Electrical > Basic characteristics from the context menu.

The Basic characteristics option generates different plots depending on the values you specify for the Modeling option, On-state behavior and losses, and Integral protection diode parameters of the MOSFET (Ideal, Switching) block. If you model the switching device with an integral protection diode, the Basic characteristics option plots the I-V characteristics for both the switching device and the diode. If you enable the thermal port of the block, the Basic characteristics option also generates surface plots of the turn-on energy loss and turn-off energy loss as functions of the on-state current and off-state voltage. For more information about this option, see Plot Basic I-V Characteristics of Semiconductor Blocks.

Examples

Power Factor Correction for CCM Boost Converter

Correct the power factor using a PFC pre-converter. This technique is useful when non-linear impedances, such as Switch Mode Power Supplies, are connected to an AC grid. As the current flowing through the inductor is never zero during the switching cycle, the boost converter operates in Continuous Conduction Mode (CCM). The inductor current and the output voltage profiles are controlled using simple integral control. During start up, the reference output voltage is ramped up to the desired voltage.

• Open Model

Quantifying IGBT Thermal Losses

The generation of a temperature profile based on switching and conduction losses in an insulated-gate bipolar transistor (IGBT). There are two buck converters. For one converter, the IGBT attaches to a Foster thermal model. For the other converter, the IGBT attaches to a Cauer thermal model. The parameters for the thermal models are tuned to give roughly equivalent results. At a simulation time of 50ms, the driving frequency changes from 40kHz to 20kHz, which increases the conduction losses and decreases the switching losses. The change in the losses results in a corresponding change in the temperature of the IGBT.

• Open Model

Totem-Pole PFC

Control the rectified voltage in a totem-pole power factor correction (PFC) circuit. MOSFETs Q1 and Q2 form the 50 kHz fast switching leg. MOSFETs Q3 and Q4 form the line frequency slow switching leg. The control subsystem uses a PI-based cascade control structure. The Scopes subsystem contains scopes that allow you to see the simulation results.

• Open Model

Ports

The figure shows the block port names.

Conserving

G — Gate terminal

electrical

Port associated with the gate terminal. You can set the port to either a physical signal or electrical port.

S — Source terminal

electrical

Electrical conserving port associated with the source terminal.

D — Drain terminal

electrical

Electrical conserving port associated with the drain terminal.

H — Thermal port

thermal

Thermal conserving port.

Dependencies

To enable this port, set Modeling option to Show thermal port.

HDiode — Thermal port for integral protection diode

thermal

Since R2024b

Thermal conserving port associated with the integral protection diode.

Dependencies

To enable this port, select the Separate thermal port for integral diode parameter.

Parameters

Modeling option — Thermal port visibility

No thermal port (default) | Show thermal port

Whether to enable the thermal port.

Main

This table shows how the visibility of Main parameters depends on how you configure the Modeling option and On-state behavior and switching losses parameters. To learn how to read this table, see Parameter Dependencies.

Main Parameter Dependencies

Parameters and Options
Modeling option
No thermal port				Show thermal port
Gate-control port				Gate-control port
Drain-source on resistance, R_DS(on)				Threshold voltage, Vth
Off-state conductance				On-state behavior and switching losses
				Specify constant values	Tabulate
Threshold voltage, Vth				Drain-source on resistance, R_DS(on)	On-state voltage, Vds(Tj,Ids)
				Off-state conductance	Temperature vector, Tj
					Drain-source current vector, Ids
					Off-state conductance

Gate-control port — Option to specify physical or electrical control port

PS (default) | Electrical

Option to specify physical or electrical control port for the switch gate.

Note

If you set this parameter to Electrical, use an internal or external reverse diode along with this block. For numerical considerations, the forward voltage of the diode must be smaller than the value of the Threshold voltage, Vth parameter of this block.

On-state behavior and switching losses — On-state behavior and switching losses

Specify constant values (default) | Tabulate

Parameterization method for on-state behavior and switching losses, specified as one of these values:

• Specify constant values — Use scalar values to specify the output current, switch-on loss, and switch-off loss data. The block assumes that the energy dissipated during a single switch-on or switch-off event scales linearly with the off-state voltage and on-state current. The block also assumes that the losses are independent of temperature.

• Tabulate — Use vectors to specify the output current and temperature data. Use arrays to specify the switch-on loss and switch-off loss data.

Dependencies

See the Main Parameter Dependencies table.

Drain-source on resistance, R_DS(on) — Drain-source on resistance

0.01 Ohm (default)

Drain-source resistance when the device is on.

Dependencies

See the Main Parameter Dependencies table.

Off-state conductance — Off-state conductance

1e-6 1/Ohm (default)

Drain-source conductance when the device is off. The value must be less than 1/R, where R is the value of On-state resistance.

Dependencies

See the Main Parameter Dependencies table.

Threshold voltage, Vth — Threshold voltage

2 V (default)

Gate-source voltage threshold. The device turns on when the gate-source voltage is above this value.

Dependencies

See the Main Parameter Dependencies table.

On-state voltage, Vds(Tj,Ids) — On-state voltage

[0, 1.8, 3.2, 6, 10, 16; 0, 2, 5.5, 9.5, 15, 25] V (default) | matrix of nonnegative scalars

Voltage drop across the device in a triggered conductive state. This parameter is a function of temperature and final on-state output current.

Dependencies

See the Main Parameter Dependencies table.

Temperature vector, Tj — Temperature values

[298.15, 448.15] K (default)

Temperature values that correspond to the on-state voltage, Vds(Tj,Ids) parameter.

Dependencies

See the Main Parameter Dependencies table.

Drain-source current vector, Ids — Drain-source current vector

[0, 20, 40, 60, 80, 100] A (default)

Drain-source currents for which the on-state voltage is defined. The first element must be zero. Specify this parameter using a vector quantity.

Dependencies

See the Main Parameter Dependencies table.

Switching Losses

To enable these parameters, set Modeling option to Show thermal port.

Switch-on loss — Switch-on loss

22.86e-3 J (default) | positive scalar

Energy dissipated during a single switch-on event.

Dependencies

To enable this parameter, set On-state behavior and switching losses to Specify constant values.

Switch-off loss — Switch-off loss

17.14e-3 J (default) | positive scalar

Energy dissipated during a single switch-off event.

Dependencies

To enable this parameter, set On-state behavior and switching losses to Specify constant values.

Off-state Vds voltage for switching loss data — Off-state drain-source voltage for switching loss data

300 V (default) | positive scalar

Output voltage of the device during the off state. This voltage is the blocking voltage at which you quote the switch-on loss and switch-off loss.

Dependencies

To enable this parameter, choose one of these options:

• Set On-state behavior and switching losses to Specify constant values.

• Set On-state behavior and switching losses to Tabulate and clear the Include switching loss tabulation with off-state Vds voltage parameter.

On-state current for switching loss data — On-state current for switching loss data

600 A (default) | positive scalar

Output current at which you quote the switch-on loss and switch-off loss.

Dependencies

To enable this parameter, set On-state behavior and switching losses to Specify constant values.

Use last on-state current from previous cycle for turn-on loss — Option to use last on-state current from previous cycle for turn-on loss

Off (default) | On

Since R2023b

Option to use the last on-state current from the previous cycle for the turn-on loss.

Use last off-state voltage from previous cycle for turn-off loss — Option to use last off-state voltage from previous cycle for turn-off loss

Off (default) | On

Since R2023b

Option to use the last off-state voltage from the previous cycle for the turn-off loss.

Switch-on loss, Eon(Tj,Ids) — Switch-on loss

[0, 55.04, 124.57, 235.53, 362.12; 0, 71.25, 161.25, 304.88, 468.75] * 1e-6 J (default) | matrix of nonnegative scalars

Energy dissipated during a single switch-on event as a function of temperature and on-state current.

Dependencies

To enable this parameter, set On-state behavior and switching losses to Tabulate and clear the Include switching loss tabulation with off-state Vds voltage parameter.

Switch-off loss, Eoff(Tj,Ids) — Switch-off loss

[0, 18, 30, 56.1, 76.5; 0, 22.5, 37.5, 70.13, 95.63] * 1e-6 J (default) | matrix of nonnegative scalars

Energy dissipated during a single switch-off event as a function of temperature and on-state current.

Dependencies

To enable this parameter, set On-state behavior and switching losses to Tabulate and clear the Include switching loss tabulation with off-state Vds voltage parameter.

Temperature vector for switching losses, Tj — Temperature for switching losses

[298.15, 448.15] K (default) | vector

Temperature values at which you quote the switch-on loss and switch-off loss.

Dependencies

To enable this parameter, set On-state behavior and switching losses to Tabulate.

Drain-source current vector for switching losses, Ids — Drain-source current vector for switching losses

[0, 10, 20, 30, 40] A (default) | vector of nonnegative scalars

Drain-source currents at which you quote the switch-on loss and switch-off-loss. The first element must be 0.

Dependencies

To enable this parameter, set On-state behavior and switching losses to Tabulate.

Include switching loss tabulation with off-state Vds voltage — Option to tabulate switching losses with off-state drain-source voltage

Off (default) | On

Since R2023b

Option to tabulate the switching losses with the off-state drain-source voltage.

To tabulate the switch-on loss and switch-off loss with the on-state drain-source current and temperature, clear this parameter. The block assumes that the losses scale linearly with the off-state drain-source voltage.

To tabulate the switch-on loss and switch-off loss with the temperature, on-state drain-source current, and off-state drain-source voltage, select this parameter.

Dependencies

To enable this parameter, set On-state behavior and switching losses to Tabulate.

Switch-on loss, Eon(Tj,Ids,Vds) — Switch-on loss

[zeros(2, 5, 3)] J (default) | 3-D array of nonnegative scalars

Since R2023b

Energy dissipated during a single switch-on event as a function of temperature, on-state drain-source current, and off-state drain-source voltage.

Dependencies

To enable this parameter, set On-state behavior and switching losses to Tabulate and select the Include switching loss tabulation with off-state Vds voltage parameter.

Switch-off loss, Eoff(Tj,Ids,Vds) — Switch-off loss

[zeros(2, 5, 3)] J (default) | 3-D array of nonnegative scalars

Since R2023b

Energy dissipated during a single switch-off event as a function of temperature, on-state drain-source current, and off-state drain-source voltage.

Dependencies

To enable this parameter, set On-state behavior and switching losses to Tabulate and select the Include switching loss tabulation with off-state Vds voltage parameter.

Off-state Vds voltage vector for switching loss data — Off-state Vds voltage vector for switching loss data

[0, 150, 300] V (default) | vector

Since R2023b

Off-state drain-source voltages at which you quote the switch-on loss and switch-off loss.

Dependencies

To enable this parameter, set On-state behavior and switching losses to Tabulate and select the Include switching loss tabulation with off-state Vds voltage parameter.

Integral Diode

Integral protection diode — Protection diode

Diode with no dynamics (default) | External diode | Diode with charge dynamics

Block integral protection diode.

The diodes you can select are:

• External diode — Do not model any integral diode inside this block and use an external diode.

• Diode with no dynamics

• Diode with charge dynamics

Diode model — Diode model

Piecewise Linear (default) | Tabulated I-V curve

Select one of these diode models:

• Piecewise Linear — Use a piecewise linear model for the diode, as described in Piecewise Linear Diode. This is the default method.

• Tabulated I-V curve — Use tabulated forward bias I-V data plus fixed reverse bias off conductance.

Dependencies

This parameter is visible only when the thermal port is exposed and the Integral protection diode parameter is set to Diode with no dynamics or Diode with charge dynamics.

Table type — Tabulated function

Table in If(Tj,Vf) form (default) | Table in Vf(Tj,If) form

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

Dependencies

This parameter is visible only when the thermal port is exposed and the Integral protection diode parameter is set to Diode with no dynamics or Diode with charge dynamics and Diode model is set to Tabulated I-V curve.

Reverse I-V characteristics type — Type of reverse I-V characteristics

Specify off conductance (default) | Tabulate

Since R2024a

Whether to specify the reverse I-V characteristics by using the diode off conductance or by tabulating the current as a function of temperature and voltage or the voltage as a function of temperature and current.

Dependencies

This parameter is visible only when the thermal port is exposed and the Integral protection diode parameter is set to Diode with no dynamics or Diode with charge dynamics and Diode model is set to Tabulated I-V curve.

Forward voltage — Forward voltage

0.8 V (default)

Minimum voltage required across the + and - block ports for the gradient of the diode I-V characteristic to be 1/R_on, where R_on is the value of On resistance.

Dependencies

To enable this parameter:

• If the thermal port is hidden, set Integral protection diode to Diode with no dynamics or Diode with charge dynamics.

• If the thermal port is exposed, set Integral protection diode to Diode with no dynamics or Diode with charge dynamics and Diode model to Piecewise linear.

On resistance — On resistance

0.001 Ohm (default)

Rate of change of voltage versus current above the Forward voltage.

Dependencies

To enable this parameter:

• If the thermal port is hidden, set Integral protection diode to Diode with no dynamics or Diode with charge dynamics.

• If the thermal port is exposed, set Integral protection diode to Diode with no dynamics or Diode with charge dynamics and Diode model to Piecewise linear.

Forward currents, If(Tj,Vf) — Vector of forward currents

[.07, .12, .19, 1.75, 4.24, 7.32, 11.2; .16, .3, .72, 2.14, 4.02, 6.35, 9.12] A (default) | nonnegative vector

Forward currents. This parameter must be a vector of at least three nonnegative elements.

Dependencies

To enable this parameter, expose the thermal port and set Diode model to Tabulated I-V curve and Table type to Table in If(Tj,Vf) form.

Junction temperatures, Tj — Vector of junction temperatures

[25, 125] degC (default)

Vector of junction temperatures. This parameter must be a vector of at least two elements.

Dependencies

To enable this parameter, expose the thermal port and set Diode model to Tabulated I-V curve.

Forward voltages, Vf — Vector of forward voltages

[.5, .7, .9, 1.3, 1.7, 2.1, 2.5] V (default)

Vector of forward voltages. This parameter must be a vector of at least three nonnegative values.

Dependencies

To enable this parameter, expose the thermal port and set Diode model to Tabulated I-V curve and Table type to Table in If(Tj,Vf) form.

Forward voltages, Vf(Tj,If) — Vector of forward voltages

[.9, 1.15, 1.25, 1.5, 1.75, 2.17, 2.6, 2.85; .58, .68, .75, 1.1, 1.38, 1.77, 2.27, 2.7] V (default) | nonnegative vector

Forward voltages. This parameter must be a vector of at least three nonnegative elements.

Dependencies

To enable this parameter, expose the thermal port and set Diode model to Tabulated I-V curve and Table type to Table in Vf(Tj,If) form.

Forward currents, If — Vector of forward currents

[.1, .2, .5, 1, 2, 4, 7, 10] A (default)

Vector of forward currents. This parameter must be a vector of at least three nonnegative values.

Dependencies

To enable this parameter, expose the thermal port and set Diode model to Tabulated I-V curve and Table type to Table in Vf(Tj,If) form.

Reverse currents, Ir(Tj,Vr) — Vector of reverse currents

[1e-06, 2e-06, 5e-06, 1e-05, 2.5e-05, 5e-05, .0001; 2e-06, 5e-06, 1e-05, 4e-05, 8e-05, .0002, .0005] A (default) | nonnegative vector

Since R2024a

Reverse currents. This parameter must be a vector of at least three nonnegative elements.

Dependencies

To enable this parameter, set:

• Modeling option to Show thermal port

• Integral protection diode to Diode with no dynamics or Diode with charge dynamics

• Diode model to Tabulated I-V curve

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

• Reverse I-V characteristics to Tabulate

Reverse voltages, Vr — Vector of reverse voltages

[10, 20, 40, 50, 70, 80, 100] V (default) | nonnegative vector

Since R2024a

Vector of reverse voltages. This parameter must be a vector of at least three nonnegative values.

Dependencies

To enable this parameter, set:

• Modeling option to Show thermal port

• Integral protection diode to Diode with no dynamics or Diode with charge dynamics

• Diode model to Tabulated I-V curve

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

• Reverse I-V characteristics to Tabulate

Reverse voltages, Vr(Tj,Ir) — Vector of reverse voltages

[10, 100, 200, 250, 300, 325, 350; 10, 70, 160, 220, 270, 300, 320] V (default) | nonnegative vector

Since R2024a

Reverse voltages. This parameter must be a vector of at least three nonnegative elements.

Dependencies

To enable this parameter, set:

• Modeling option to Show thermal port

• Integral protection diode to Diode with no dynamics or Diode with charge dynamics

• Diode model to Tabulated I-V curve

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

• Reverse I-V characteristics to Tabulate

Reverse currents, Ir — Vector of reverse currents

[1e-06, 2e-06, 5e-06, 1e-05, 2e-05, 5e-05, .0001] A (default) | nonnegative vector

Since R2024a

Vector of reverse currents. This parameter must be a vector of at least three nonnegative values.

Dependencies

To enable this parameter, set:

• Modeling option to Show thermal port

• Integral protection diode to Diode with no dynamics or Diode with charge dynamics

• Diode model to Tabulated I-V curve

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

• Reverse I-V characteristics to Tabulate

Off conductance — Off conductance

1e-5 1/Ohm (default)

Conductance of the reverse-biased diode.

Dependencies

This parameter is visible only when the Integral protection diode parameter is set to Diode with no dynamics or Diode with charge dynamics and Reverse I-V characteristics type is set to Specify off conductance.

Reverse recovery loss model — Model for reverse recovery loss

Fixed loss (default) | Tabulated loss

Since R2023a

Whether to model fixed or tabulated reverse recovery losses.

Dependencies

To enable this parameter, set the Modeling option parameter to Show thermal port and set the Integral protection diode parameter to Diode with no dynamics.

Reverse recovery loss — Reverse recovery loss

0 J (default) | nonnegative scalar

Since R2023a

Dissipated energy in each turn-off event, regardless of the state of the diode before or after the switching event.

Dependencies

To enable this parameter, set the Reverse recovery loss model parameter to Fixed loss.

Scale reverse recovery loss with current and voltage — Option to scale reverse recovery loss

On (default) | Off

Since R2023b

Option to scale reverse recovery loss with current and voltage.

Dependencies

To enable this parameter:

• Set Modeling option to Show thermal port.

• Set Integral protection diode to Diode with no dynamics.

• Set Reverse recovery loss model to Fixed loss.

Reverse recovery loss table, Erect(Tj), If — Reverse recovery loss

zeros(2,3) J (default) | vector of nonnegative scalars

Since R2023a

Dissipated energy as a function of the forward current If just before the switching event, and final off-state voltage once the diode is in off state.

Dependencies

To enable this parameter, set the Reverse recovery loss model parameter to Tabulated loss.

Temperature vector for recovery loss table, Tj — Temperature vector for recovery loss table

[298.15 398.15] K (default) | vector

Since R2023a

Temperature vector used to tabulate reverse recovery loss.

Dependencies

To enable this parameter, set the Reverse recovery loss model parameter to Tabulated loss.

Forward current vector for recovery loss table, If — Forward current vector for recovery loss table

[.1, 1, 10] K (default) | vector of nonnegative scalars

Since R2023a

Forward current vector used to tabulate reverse recovery loss.

Dependencies

To enable this parameter, set the Reverse recovery loss model parameter to Tabulated loss.

Forward current when measuring recovery loss, Irec — Forward current when the block measures recovery loss

10 A (default) | positive scalar

Since R2023b

Forward current through the diode before the reverse recovery event that the block uses to measure recovery loss.

Dependencies

To enable this parameter, set Reverse recovery loss model to Fixed loss and select the Scale reverse recovery loss with current and voltage parameter.

Turn-off voltage when measuring recovery loss, Vrec — Turn-off voltage when measuring recovery loss

10 V (default) | positive scalar

Since R2023a

Voltage across the diode after the reverse recovery event used to measure recovery loss.

Dependencies

To enable this parameter, choose from one of these options:

• Set Reverse recovery loss model to Fixed loss and select the Scale reverse recovery loss with current and voltage parameter.

• Set the Reverse recovery loss model parameter to Tabulated loss.

Filter time constant for voltage and current values — Filter time constant for voltage and current values

1 / 1000 / 100 s (default) | positive scalar

Since R2023a

Filter time constant for voltage and current values used to calculate reverse recovery loss. Set this parameter to a value that is lower than the fastest switching period.

Dependencies

To enable this parameter, choose from one of these options:

• Set Reverse recovery loss model to Fixed loss and select the Scale reverse recovery loss with current and voltage parameter.

• Set the Reverse recovery loss model parameter to Tabulated loss.

Junction capacitance — Junction capacitance

50e-9 F (default)

Diode junction capacitance.

Dependencies

This parameter is visible only when the Integral protection diode parameter is set to Diode with charge dynamics.

Peak reverse current, iRM — Peak reverse current

-235 A (default) | negative scalar

Peak reverse current measured by an external test circuit. This value must be less than zero. The default value is -235 A.

Dependencies

This parameter is visible only when the Integral protection diode parameter is set to Diode with charge dynamics.

Initial forward current when measuring iRM — Initial forward current when measuring iRM

300 A (default) | positive scalar

Initial forward current when measuring peak reverse current. This value must be greater than zero.

Dependencies

This parameter is visible only when the Integral protection diode parameter is set to Diode with charge dynamics.

Rate of change of current when measuring iRM — Rate of change of current when measuring iRM

-50A/μs (default) | negative scalar

Rate of change of current when measuring peak reverse current. This value must be less than zero.

Dependencies

This parameter is visible only when the Integral protection diode parameter is set to Diode with charge dynamics.

Reverse recovery time parameterization — Reverse recovery time parameterization

Specify reverse recovery time directly (default) | Specify stretch factor | Specify reverse recovery charge

Determines how you specify reverse recovery time in the block. The default value is Specify reverse recovery time directly.

If you select Specify stretch factor or Specify reverse recovery charge, you specify a value that the block uses to derive the reverse recovery time. For more information on these options, see How the Block Calculates TM and Tau.

Dependencies

This parameter is visible only when the Integral protection diode parameter is set to Diode with charge dynamics.

Reverse recovery time, trr — Reverse recovery time

15 μs (default)

Interval between the time when the current initially goes to zero (when the diode turns off) and the time when the current falls to less than 10% of the peak reverse current. The value of the Reverse recovery time, trr parameter must be greater than the value of the Peak reverse current, iRM parameter divided by the value of the Rate of change of current when measuring iRM parameter.

Dependencies

This parameter is visible only when the Integral protection diode parameter is set to Diode with charge dynamics and the Reverse recovery time parameterization parameter is set to Specify reverse recovery time directly.

Reverse recovery time stretch factor — Reverse recovery time stretch factor

3 (default)

Value that the block uses to calculate Reverse recovery time, trr. This value must be greater than 1. Specifying the stretch factor is an easier way to parameterize the reverse recovery time than specifying the reverse recovery charge. The larger the value of the stretch factor, the longer it takes for the reverse recovery current to dissipate.

Dependencies

This parameter is visible only when the Integral protection diode parameter is set to Diode with charge dynamics and the Reverse recovery time parameterization parameter is set to Specify stretch factor.

Reverse recovery charge, Qrr — Reverse recovery charge

1500 μAs (default)

Value that the block uses to calculate Reverse recovery time, trr. Use this parameter if the data sheet for your diode device specifies a value for the reverse recovery charge instead of a value for the reverse recovery time.

The reverse recovery charge is the total charge that continues to dissipate when the diode turns off. The value must be less than $$-\frac{i^2{}_{RM}}{2a},$$

where:

• i_RM is the value specified for Peak reverse current, iRM.

• a is the value specified for Rate of change of current when measuring iRM.

Dependencies

This parameter is visible only when the Integral protection diode parameter is set to Diode with charge dynamics and the Reverse recovery time parameterization parameter is set to Specify reverse recovery charge.

Diode turn-off voltage when measuring Erec — Diode turn-off voltage when measuring Erec

-600 V (default)

Voltage between the diode in steady-state.

Dependencies

This parameter is visible only when the Integral protection diode parameter is set to Diode with charge dynamics and the Reverse recovery time parameterization parameter is set to Specify reverse recovery energy.

Stray inductance when measuring Erec — Stray inductance when measuring Erec

150 nH (default)

Total unintended inductance in the measurement circuit. The block uses this value to calculate Reverse recovery energy, Erec.

Dependencies

This parameter is visible only when the Integral protection diode parameter is set to Diode with charge dynamics and the Reverse recovery time parameterization parameter is set to Specify reverse recovery energy.

Reverse recovery energy, Erec — Reverse recovery energy

0.03 J (default)

Total switching losses due to the diode reverse recovery.

Dependencies

This parameter is visible only when the Integral protection diode parameter is set to Diode with charge dynamics and the Reverse recovery time parameterization parameter is set to Specify reverse recovery energy.

For more information on these parameters, see Diode.

Thermal Port

Separate thermal port for integral diode — Option to separate thermal port for integral diode

off (default) | on

Since R2024b

Whether to separate the thermal port for the integral protection diode of the device.

Dependencies

To enable this parameter, set Modeling option to Show thermal port and, in the Integral Diode section, set Integral protection diode to Diode with no dynamics or Diode with charge dynamics.

Thermal network — Options for thermal network modeling

External (default) | Specify junction and case thermal parameters | Cauer model | Cauer model parameterized with Foster coefficients

Options for modeling the thermal network of the block.

Thermal mass parameterization — Option to parameterize thermal mass

By thermal time constants (default) | By thermal mass

Options to parameterize the thermal mass:

• By thermal time constants — Parameterize the thermal masses in terms of thermal time constants.

• By thermal mass — Specify the thermal mass values directly.

Dependencies

To enable this parameter, set Thermal network to Specify junction and case thermal parameters, Cauer model, or Cauer model parameterized with Foster coefficients.

Junction case and case-ambient (or case-heatsink) thermal resistances, [R_JC R_CA] — Junction case and case-ambient (or case-heatsink) thermal resistances

[.03, .2] K/W (default) | vector of positive values

Row vector [ R_JC R_CA ] of two thermal resistance values, represented by two Conductive Heat Transfer blocks. The first value, R_JC, is the thermal resistance between the junction and the case. The second value, R_CA, is the thermal resistance between port H and the device case.

Dependencies

To enable this parameter, set Thermal network to Specify junction and case thermal parameters.

Junction and case thermal time constants, [t_J t_C] — Junction and case thermal time constants

[.1, 5] s (default) | vector of positive values

Row vector [ t_J t_C ] of two thermal time constant values. The first value, t_J, is the junction time constant. The second value, t_C, is the case time constant.

Dependencies

To enable this parameter, set Thermal network to Specify junction and case thermal parameters and Thermal mass parameterization to By thermal time constants.

Junction and case thermal masses, [M_J M_C] — Junction and case thermal masses

[3, 25] J/K (default) | vector of positive values

Row vector [ M_J M_C ] of two thermal mass values. The first value, M_J, is the junction thermal mass. The second value, M_C, is the case thermal mass.

Dependencies

To enable this parameter, set Thermal network to Specify junction and case thermal parameters and Thermal mass parameterization to By thermal mass.

Junction and case initial temperatures, [T_J T_C] — Junction and case initial temperatures

[25, 25] degC (default) | vector of positive values

Row vector [ T_J T_C ] of two temperature values. The first value, T_J, is the junction initial temperature. The second value, T_C, is the case initial temperature.

Dependencies

To enable this parameter, set Thermal network to Specify junction and case thermal parameters.

Diode junction case and case-ambient (or case-heatsink) thermal resistances, [R_JC R_CA] — Junction case and case-ambient (or case-heatsink) thermal resistances for integral diode

[.03, .2] K/W (default) | vector of positive values

Since R2024b

Row vector [ R_JC R_CA ] of two thermal resistance values, represented by two Conductive Heat Transfer blocks, for the integral protection diode. The first value, R_JC, is the thermal resistance between the junction and the case. The second value, R_CA, is the thermal resistance between port HDiode and the diode case.

Dependencies

To enable this parameter:

• In the Integral Diode section, set Integral protection diode to Diode with no dynamics or Diode with charge dynamics.

• In the Thermal Port section:

  • Select the Separate thermal port for integral diode parameter.

  • Set Thermal network to Specify junction and case thermal parameters.

Thermal time constants of diode junction and case, [t_J t_C] — Junction and case thermal time constants for integral diode

[.1, 5] s (default) | vector of positive values

Since R2024b

Row vector [ t_J t_C ] of two thermal time constant values for the integral protection diode. The first value, t_J, is the junction time constant. The second value, t_C, is the case time constant.

Dependencies

To enable this parameter:

• In the Integral Diode section, set Integral protection diode to Diode with no dynamics or Diode with charge dynamics.

• In the Thermal Port section:

  • Select the Separate thermal port for integral diode parameter.

  • Set Thermal network to Specify junction and case thermal parameters.

  • Set Thermal mass parameterization to By thermal time constants.

Thermal masses of diode junction and case, [M_J M_C] — Thermal masses of diode junction and case

[3, 25] J/K (default) | vector of positive values

Since R2024b

Row vector [ M_J M_C ] of two thermal mass values for the integral protection diode. The first value, M_J, is the junction thermal mass. The second value, M_C, is the case thermal mass.

Dependencies

To enable this parameter:

• In the Integral Diode section, set Integral protection diode to Diode with no dynamics or Diode with charge dynamics.

• In the Thermal Port section:

  • Select the Separate thermal port for integral diode parameter.

  • Set Thermal network to Specify junction and case thermal parameters.

  • Set Thermal mass parameterization to By thermal mass.

Initial temperatures of diode junction and case, [T_J T_C] — Initial temperatures of diode junction and case

[25, 25] degC (default) | vector of positive values

Since R2024a

Row vector [ T_J T_C ] of two temperature values for the integral protection diode. The first value, T_J, is the junction initial temperature. The second value, T_C, is the case initial temperature.

Dependencies

To enable this parameter:

• In the Integral Diode section, set Integral protection diode to Diode with no dynamics or Diode with charge dynamics.

• In the Thermal Port section:

  • Select the Separate thermal port for integral diode parameter.

  • Set Thermal network to Specify junction and case thermal parameters.

Thermal resistances, [R1 R2 … Rn] — Thermal resistances

[.03, .1, .2] K/W (default) | [.03, .2] K/W | vector of positive values

Row vector of n thermal resistance values, represented by the Cauer elements used in the thermal network.

If you set Thermal network to Cauer model, the default value is [.03, .1, .2]. If you set Thermal network to Cauer model parameterized with Foster coefficients, the default value is [.03, .2].

Dependencies

To enable this parameter, set Thermal network to Cauer model or Cauer model parameterized with Foster coefficients.

Thermal time constants, [t1 t2 … tn] — Thermal time constants

[.1, 1, 5] s (default) | [1, 10] s | vector of positive values

Row vector of n thermal time constant values, where n is the number of Cauer elements used in the thermal network. The length of this vector must match the length of Thermal resistances, [R1 R2 … Rn]. With this parameterization, the thermal masses are computed as Mi = ti/Ri, where Mi, ti and Ri are the thermal mass, thermal time, and thermal resistance for the i^th Cauer element (if you set Thermal network to Cauer model) or Foster element (if you set Thermal network to Cauer model parameterized with Foster coefficients).

If you set Thermal network to Cauer model, the default value is [.1, 1, 5]. If you set Thermal network to Cauer model parameterized with Foster coefficients, the default value is [1, 10].

Dependencies

To enable this parameter, set Thermal network to Cauer model or Cauer model parameterized with Foster coefficientsand Thermal mass parameterization to By thermal time constants.

Thermal masses, [M1 M2 … Mn] — Thermal masses

[3, 10, 25] J/K (default) | [33, 50] J/K | vector of positive values

Row vector of n thermal mass values, where n is the number of Cauer elements used in the thermal network.

If you set Thermal network to Cauer model, the default value is [3, 10, 25]. If you set Thermal network to Cauer model parameterized with Foster coefficients, the default value is [33, 50].

Dependencies

To enable this parameter, set Thermal network to Cauer model or Cauer model parameterized with Foster coefficients and Thermal mass parameterization to By thermal mass.

Thermal masses initial temperatures, [T1 T2 … Tn] — Thermal masses initial temperatures

[25, 25, 25] degC (default) | vector of positive values

Row vector of temperature values that corresponds to the temperature drop across each thermal capacity in the model.

Dependencies

To enable this parameter, set Thermal network to Cauer model.

Diode thermal resistances, [R1 R2 … Rn] — Thermal resistances for integral diode

[.03, .1, .2] K/W (default) | [.03, .2] K/W | vector of positive values

Since R2024b

Row vector of n thermal resistance values for the integral protection diode, represented by the Cauer elements used in the thermal network.

If you set Thermal network to Cauer model, the default value is [.03, .1, .2]. If you set Thermal network to Cauer model parameterized with Foster coefficients, the default value is [.03, .2].

Dependencies

To enable this parameter:

• In the Integral Diode section, set Integral protection diode to Diode with no dynamics or Diode with charge dynamics.

• In the Thermal Port section:

  • Select the Separate thermal port for integral diode parameter.

  • Set Thermal network to Cauer model or Cauer model parameterized with Foster coefficients.

Diode thermal time constants, [t1 t2 … tn] — Thermal time constants for integral diode

[.1, 1, 5] s (default) | [1, 10] s | vector of positive values

Since R2024b

Row vector of n thermal time constant values for the integral protection diode, where n is the number of Cauer elements used in the thermal network. The length of this vector must match the length of Diode thermal resistances, [R1 R2 … Rn]. With this parameterization, the thermal masses are computed as Mi = ti/Ri, where Mi, ti and Ri are the thermal mass, thermal time, and thermal resistance for the i^th Cauer element (if you set Thermal network to Cauer model) or Foster element (if you set Thermal network to Cauer model parameterized with Foster coefficients).

If you set Thermal network to Cauer model, the default value is [.1, 1, 5]. If you set Thermal network to Cauer model parameterized with Foster coefficients, the default value is [1, 10].

Dependencies

To enable this parameter:

• In the Integral Diode section, set Integral protection diode to Diode with no dynamics or Diode with charge dynamics.

• In the Thermal Port section:

  • Select the Separate thermal port for integral diode parameter.

  • Set Thermal network to Cauer model or Cauer model parameterized with Foster coefficients.

  • Set Thermal mass parameterization to By thermal time constants.

Diode thermal masses, [M1 M2 … Mn] — Thermal masses for integral diode

[3, 10, 25] J/K (default) | [33, 50] J/K | vector of positive values

Since R2024b

Row vector of n thermal mass values for the integral protection diode, where n is the number of Cauer elements used in the thermal network.

If you set Thermal network to Cauer model, the default value is [3, 10, 25]. If you set Thermal network to Cauer model parameterized with Foster coefficients, the default value is [33, 50].

Dependencies

To enable this parameter:

• In the Integral Diode section, set Integral protection diode to Diode with no dynamics or Diode with charge dynamics.

• In the Thermal Port section:

  • Select the Separate thermal port for integral diode parameter.

  • Set Thermal network to Cauer model or Cauer model parameterized with Foster coefficients.

  • Set Thermal mass parameterization to By thermal mass.

Initial temperatures of diode thermal masses, [T1 T2 … Tn] — Initial temperatures of diode thermal masses

[25, 25, 25] degC (default) | vector of positive values

Since R2024b

Row vector of temperature values for the integral protection diode. This parameter corresponds to the temperature drop across each thermal capacity in the model.

Dependencies

To enable this parameter:

• In the Integral Diode section, set Integral protection diode to Diode with no dynamics or Diode with charge dynamics.

• In the Thermal Port section:

  • Select the Separate thermal port for integral diode parameter.

  • Set Thermal network to Cauer model.

Initial node temperatures, [T1 T2 ... Tn] — Initial node temperatures

[25, 25, 25, 25] degC (default) | vector of positive values

Row vector of absolute temperature values of each node starting from the junction.

Dependencies

To enable this parameter, set Thermal network to Cauer model parameterized with Foster coefficients.

Diode initial node temperatures, [T1 T2 ... Tn] — Initial node temperatures for integral diode

[25, 25, 25, 25] degC (default) | vector of positive values

Since R2024b

Row vector of absolute temperature values of each node starting from the integral protection diode junction.

Dependencies

To enable this parameter:

• In the Integral Diode section, set Integral protection diode to Diode with no dynamics or Diode with charge dynamics.

• In the Thermal Port section:

  • Select the Separate thermal port for integral diode parameter.

  • Set Thermal network to Cauer model parameterized with Foster coefficients.

Junction thermal mass — Thermal mass of junction

0.1 J/K (default) | positive scalar

Thermal mass of the junction.

Dependencies

To enable this parameter, set Thermal network to External.

Diode junction thermal mass — Thermal mass of diode junction

0.1 J/K (default) | positive scalar

Since R2024b

Thermal mass of the diode junction.

Dependencies

To enable this parameter:

• In the Integral Diode section, set Integral protection diode to Diode with no dynamics or Diode with charge dynamics.

• In the Thermal Port section:

  • Select the Separate thermal port for integral diode parameter.

  • Set Thermal network to External.

For more information about using thermal ports and for the other Thermal Port parameters, see Simulating Thermal Effects in Semiconductors.

Extended Capabilities

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

Version History

Introduced in R2013b

R2024b: Separate thermal port for integral diode

You can now separate the thermal port for the integral protection diode of the MOSFET (Ideal, Switching) block from the H port. To separate the thermal ports:

• Set the Modeling option parameter to Show thermal port

• In the Integral Diode section, set the Integral protection diode parameter to Diode with no dynamics or Diode with charge dynamics.

• In the Thermal port section, select the Separate thermal port for integral diode parameter.

R2024a: Model tabulated reverse I-V characteristics

You can now model the reverse I-V characteristics for the MOSFET (Ideal, Switching) block by tabulating the current as a function of temperature and voltage or the voltage as a function of temperature and current.

Before R2024a, you can only model the reverse I-V characteristics by specifying the off conductance of the reverse-biased diode.

R2023b: Scale reverse recovery loss with current and voltage

You can now scale a fixed reverse recovery loss value with current and voltage. To enable this option, select the Scale reverse recovery loss with current and voltage parameter.

Models you create in R2023a or earlier default to no scaling for backwards compatibility.

R2023b: Tabulate switching losses with temperature, current, and voltage

You can now tabulate switching losses with temperature, current, and voltage. In earlier releases, you can tabulate switching losses with temperature and current only.

To specify the losses as a function of the junction temperature, on-state current, and off-state voltage, set the On-state behavior and switching losses parameter to Tabulate and select the Include switching loss tabulation with off-state Vds voltage parameter.

R2023b: Determine switching losses for discontinuous load currents

The MOSFET (Ideal, Switching) block now supports discontinuous load currents.

The block supports discontinuous load currents by measuring the off-state voltage and on-state current at all turn-on and turn-off events to compute switching losses. New models behave this way by default. If you use a fixed-step solver, the shortest device on or off period is now one step. Before R2023b, the minimum period is three steps. To report switching losses, the minimum period is still three steps.

Before R2023b, the block measures the off-state voltage before turn-on and on-state current before turn-off only.

You can still use the original method of measuring the off-state voltage before turn-on and on-state current before turn-off in R2023b. Models you create in R2023a or earlier default to this behavior for backwards compatibility. The original method is designed for inductive loads with continuous currents. Use the original method if you are modeling capacitance across the switching device or switching device lead inductance:

• To model capacitance across the switching device, for example, if the parallel diode has capacitance or you are using the Lauritzen charge model, select the Use last on-state current from previous cycle for turn-on loss parameter.

• To model switching device lead inductance, select the Use last off-state voltage from previous cycle for turn-off loss parameter.

R2023b: Plot basic I-V characteristics

You can now plot the basic I-V characteristics for the MOSFET (Ideal, Switching) block, based on the current block parameter values, without simulating the model.

To plot the basic characteristics, right-click the block and select Electrical > Basic characteristics from the context menu.

If you model the switching device with an integral protection diode, the Basic characteristics option plots the I-V characteristics for both the switching device and the diode. If you enable the thermal port of the block, the Basic characteristics option also generates surface plots of the turn-on energy loss and turn-off energy loss as functions of the on-state current and off-state voltage.

R2023a: Update on integral diode modeling options

From R2023a forward, you can model reverse recovery loss in the MOSFET (Ideal, Switching) block. To enable the Reverse recovery loss model parameter, set the Modeling option parameter to Show thermal port and set the Integral protection diode parameter to Diode with no dynamics.

R2021a: Removal of energy dissipation time constant parameter

From R2021a forward, the Energy dissipation time constant parameter of the MOSFET (Ideal, Switching) block is no longer used. A step in junction temperature now reflects the switching losses. If your model contains a thermal mass directly connected to this block thermal port, remove it and model the thermal mass inside the component itself.

R2020b: Update on switching losses and thermal modeling options

From R2020b forward, the MOSFET (Ideal, Switching) block has improved losses and thermal modeling options.

As a result of these changes:

• Electrical and thermal on-state losses are now always identical. The Thermal loss dependent on parameter and its options, Voltage and current and Voltage, current, and temperature, have been renamed to On-state behavior and switching losses, Specify constant values, and Tabulate with temperature and current:

  • If you selected Voltage and current for Thermal loss dependent on, then the electrical on-state losses are unchanged and their values are determined using the on-state resistance. However, the thermal on-state losses are now also determined by the on-state resistance. Prior to R2020b, the thermal on-state losses were defined by the product of the On-state voltage and Output current, Iout parameters.

  • If you selected Voltage, current, and temperature for Thermal loss dependent on, then the thermal on-state losses are unchanged and the On-state voltage, Vds(Tj,Ids) parameter sets their values. However, the electrical on-state losses are now equal to the thermal on-state losses. Prior to R2020b, the electrical on-state losses were defined by the value of the on-state resistance.

• The On-state voltage parameter is no longer used.