Diode

R2026b

Piecewise linear, exponential, or tabulated diode

Libraries:
Simscape / Electrical / Semiconductors & Converters

Description

The Diode block models a diode with a piecewise linear, tabulated, or exponential relationship between current I and voltage V:

Piecewise linear — Specify the forward voltage, on resistance, and off conductance. The I-V curve consists of two linear regions separated by a forward voltage threshold: a high-resistance off state and a low-resistance on state.
Tabulated I-V curve — Specify tabular data for forward current as a function of junction temperature and forward voltage. The software interpolates between measured data points, with linear extrapolation beyond the tabulated range.
Exponential — Use the Shockley diode equation to model the exponential relationship between diode voltage and current. The saturation current varies with temperature based on the semiconductor energy gap.

Choose the diode model based on the level of fidelity that you need to meet your design goals and the data that you have available to parameterize the block. You manage the level of fidelity by setting the Modeling option parameter to one of these options:

Ideal — Use a piecewise linear I-V curve. The block has no thermal port. This simple model simulates quickly and does not include reverse recovery losses or charge dynamics.
Ideal with thermal losses — Choose a piecewise linear or tabulated I-V curve. The block models the reverse recovery losses as an energy loss at switching events and does not model charge dynamics. The block has an exposed thermal port.
Detailed with charge dynamics — Choose a tabulated or exponential I-V curve. The block models the charge dynamics. You can specify a fixed capacitance or a depletion-mode capacitance. You can also model charge reverse recovery using the Lauritzen charge model. The charge-dynamics model captures reverse recovery losses implicitly through continuous electrical power dissipation. The block has an optional thermal port. This model provides the highest fidelity for analyzing transient effects and loss distribution.

For more information about choosing the level of fidelity that you need to meet your design goals, see Choose Blocks to Model Semiconductor Devices.

Note

Before R2026b: The Modeling option parameter determines only whether you expose the thermal port. As a result of this change, the Diode block parameters, dependencies, and variables have changed. If you are using a previous release or working with models that you developed in a previous release, see Manage model fidelity using a simpler block mask for more information.

When you set the Modeling option parameter to Ideal, the Diode block is similar to the simpler Diode block in the Simscape™ Foundation Library. Use the Diode block in the Simscape Electrical™ library, when you want to:

Model multiple diodes in series or parallel using a single Diode block.
Model Zener diodes.
Model faults.
Plot block-level characteristics using buttons in the Utilities settings.

This table summarizes the features that each level of fidelity supports, with links to the relevant section in the documentation.

	Modeling option
	Ideal	Ideal with thermal losses	Detailed with charge dynamics
Diode model (I-V parameterization)	Piecewise Linear Diode	Piecewise Linear Diode Tabulated Diode	Tabulated Diode Exponential Diode
Zener diodes For more information, see Model Zener diode.	Supported	Supported	Supported
Reverse recovery losses	Not modeled	Modeled explicitly as an energy loss at switching events For more information, see Reverse Recovery Losses.	Included implicitly in the continuous electrical power dissipation resulting from the charge-dynamics equations
Junction capacitance	Not modeled	Not modeled	Modeled For more information, see Junction Capacitance.
Charge dynamics	Not modeled	Not modeled	Modeled For more information, see Charge dynamics.
Temperature dependence on I-V characteristics For more information, see Temperature Dependence.	Not modeled	Piecewise linear diode — Not modeled Tabulated diode — Modeled by including junction temperature in the tabular I-V data	Tabulated diode — Modeled by including junction temperature in the tabular I-V data Exponential diode — Modeled by varying saturation current with temperature based on the semiconductor energy gap
Effects of electrical losses on device temperature For more information, see Modeling Thermal Effects.	Not modeled The block converts conduction losses to heat that is external to the system.	Modeled The block converts electrical losses to heat by stepping up the junction temperature at the thermal port.	Optional If you do not enable the thermal port, the blocks converts electrical losses to heat that is external to the system. If you enable the thermal port, the block converts electrical losses to heat by stepping up the junction temperature at the thermal port.
Initial targets and nominal values For more information, see Variables.	Supported	Supported	Supported
Parameterization tools For more information, see Parameterization.	Supports predefined parameterizations	Supports predefined parameterizations Supports the `ee_importDeviceParameters` function	Supports predefined parameterizations Supports the `ee.spice.diodeSubcircuit2lookup` function
Faults For more information, see Faults.	Supported	Supported	Supported
Basic characteristics and derived data sheets For more information, see Utilities.	Supported	Supported	Supported

Piecewise Linear Diode

To model a piecewise linear diode, choose one of these options:

Set the Modeling option parameter to Ideal.
Set the Modeling option parameter to Ideal with thermal losses and set the Diode model parameter to Piecewise linear.

When the diode voltage exceeds the value of the Forward voltage parameter, the diode is forward biased and in the on state. In this region, the current increases with voltage at a gradient of 1/R_on, where R_on is the value of the On resistance parameter. Otherwise, the diode is in the off state and behaves like a linear resistor with a small conductance equal to the Off conductance parameter value, G_off. This figure shows a typical I-V curve with an exaggerated value of G_off.

Piecewise linear diode I-V curve showing off state with gradient G_off below the forward voltage and on state with gradient 1/R_on above it

If you select the Model Zener diode parameter, the I-V curve includes a third conduction region for reverse breakdown at voltages less than -BV where BV is the breakdown voltage. In this region, the current increases with increasing voltage at a gradient of 1/R_z where R_z is the Zener resistance.

Tabulated Diode

To model a diode with a tabulated I-V curve:

Set the Modeling option parameter to Ideal with thermal losses or Detailed with charge dynamics.
Set the Diode model parameter to Tabulated I-V curve.

This figure shows the implementation of the tabulated diode option:

I-V curve showing linear extrapolation outside of the central tabulated data region in both the first and third quadrant.

If you select the Model Zener Diode parameter, you can also model the tabulated reverse I-V characteristics. If you do not select the Model Zener Diode parameter, the block models the reverse characteristics by using the Off conductance parameter:

If the voltage is less than -1 V, the block models the I-V relationship with a constant off-state conductance equal to the value of the Off conductance parameter. The value you specify must be less than the gradient of the forward I-V curve for small positive voltages.
If the voltage is between -1 V and 0 V, the block uses makima interpolation so that the I-V curves for forward and reverse bias overlap smoothly.

The block uses makima interpolation to find intermediate values. If the voltage or current exceed the tabulated data range, the block uses linear extrapolation after the last I-V data point.

Exponential Diode

To model an exponential diode, set the Modeling option parameter to Detailed with charge dynamics and set the Diode model parameter to Exponential.

The exponential diode model uses this relationship between the diode current and the diode voltage,

$\begin{array}{l} I = I S \cdot (e^{\frac{q V}{N k T_{m 1}}} - 1) V > - B V \\ I = - I S \cdot (e^{\frac{- q (V + B V)}{k T_{m 1}}} - e^{\frac{q V}{N k T_{m 1}}}) V \leq - B V \end{array}$

where:

q is the elementary charge on an electron (1.602176e-19 C).
k is the Boltzmann constant (1.3806503e-23 J/K).
BV is the reverse breakdown voltage.
N is the emission coefficient.
IS is the saturation current.
T_m1 is the Measurement temperature parameter value. This parameter defines the operating temperature at which the electrical properties of the modeled device are equal to the corresponding block parameters values.

When (qV / NkT_m1) > 80, the block replaces $e^{\frac{q V}{N k T_{m 1}}}$ with (qV / NkT_m1– 79)e⁸⁰, which matches the gradient of the diode current at (qV / NkT_m1) = 80 and extrapolates linearly. When (qV / NkT_m1) < –79, the block replaces $e^{\frac{q V}{N k T_{m 1}}}$ with (qV / NkT_m1+ 80)e^–79, which also matches the gradient and extrapolates linearly. Typical electrical circuits do not reach these extreme values. The block provides this linear extrapolation to improve convergence when solving for the constraints during simulation.

If you select the Model Zener Diode parameter, the block uses the finite value of BV that you specify to model the sharp increase in reverse current as the voltage approaches -BV. If you clear this parameter, the block sets BV = inf, so the equation for V > -BV always applies.

The reverse breakdown voltage and saturation current are functions of temperature. You specify the reverse breakdown voltage at the measurement temperature using the Reverse breakdown voltage parameter. How the block calculates the saturation current at the measurement temperature depends on which option you select for the Parameterization parameter in the Main settings.

When you set Parameterization to Use parameters IS and N, you specify the saturation current and emission coefficient using the Saturation current IS and Emission coefficient N parameters.

When you set Parameterization to Use two I-V curve data points, you specify two voltage and current measurement points on the diode I-V curve and the block derives the IS and N values using these equations,

$N = ((V_{1} - V_{2}) / V_{t}) / (\log (I_{1}) - \log (I_{2}))$
$IS = (I_{1} / (\exp (V_{1} / (N V_{t})) - 1) + I_{2} / (\exp (V_{2} / (N V_{t})) - 1)) / 2$

where:

V_t = kT_m1 / q.
V₁ and V₂ are the values in the Voltages [V1 V2] vector.
I₁ and I₂ are the values in the Currents [I1 I2] vector.

When you set Parameterization to Use an I-V data point and IS, the block calculates N using this equation.

$N = V_{1} / (V_{t} \log (\frac{I_{1}}{I S} + 1))$

When you set Parameterization to Use an I-V data point and N, the block calculates IS using this equation.

$I S = I_{1} / (\exp (V_{1} / (N V_{t}) - 1))$

If you model temperature dependence, the block modifies BV and IS to account for differences between the measurement temperature and the simulation temperature. For more information, see Temperature Dependence.

Zener Diode

When a diode is sufficiently reverse biased, it enters reverse breakdown and begins to conduct in the reverse direction. To model this behavior, select the Model Zener diode parameter and specify a finite value for the Reverse breakdown voltage parameter. All three values of the Modeling option parameter support Zener diode modeling.

How the block models reverse breakdown depends on the diode I-V model:

Piecewise linear — The I-V curve gains a third conduction region below -BV, where current increases with a gradient of 1/R_z. You specify the breakdown voltage and Zener resistance.
Tabulated I-V curve — You specify the reverse I-V characteristics directly as tabulated data. This replaces the constant off-conductance you need to provide if you clear the Model Zener diode parameter. For more information, see Tabulated Diode.
Exponential — The reverse breakdown voltage BV is part of the Shockley diode equation. The block models the sharp increase in reverse current as the voltage approaches -BV. For more information, see Exponential Diode.

The Diode block icon updates automatically depending on whether you model a Zener diode and whether you expose the thermal port.

Thermal Port	Model a Zener diode Parameter Value	Block Icon
Not exposed	`Off`
Not exposed	`On`
Exposed	`Off`
Exposed	`On`

Reverse Recovery Losses

Reverse recovery loss is one of the main sources of thermal loss in diodes. When the diode turns off, current briefly continues flowing in reverse as stored charge in the junction depletes. The diode dissipates this energy every time it turns off, transitioning from its conducting state to the open-circuit state.

To model reverse recovery losses explicitly, without modeling charge dynamics, set the Modeling option parameter to Ideal with thermal losses. The block represents the losses that the charge creates during reverse recovery as an instantaneous loss. Alternatively, if you set the Modeling option parameter to Detailed with charge dynamics, the block models reverse recovery losses through continuous charge dynamics rather than instantaneous energy events. This option also supports junction capacitance modeling. For more information, see Junction Capacitance and Charge Dynamics.

This figure shows the current, reverse recovery energy, and voltage of the diode in a switching regime inside a half-bridge. The middle plot shows the energy dissipated at each turn-off event.

Three plots showing diode current, reverse recovery loss, and voltage over time in a half-bridge switching regime

The block applies reverse recovery losses by stepping up the junction temperature with a value equal to the reverse recovery loss divided by the total thermal mass at the junction.

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 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 Tabulate loss with Tj and If or Tabulate loss with Tj, If, and Vrec, the block uses a lookup table to determine the dissipated energy as a function of the junction temperature and the forward current just before the switching event. The three-dimensional option also tabulates by turn-off voltage, whereas the two-dimensional option linearly scales the losses by the off-state voltage relative to the Turn-off voltage when measuring recovery loss, Vrec parameter value. Both options use 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.

Note

The lastReverseRecoveryLoss variable in the logged simulation data includes the reverse recovery 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. To learn how to log and plot simulation data, see the Log and Plot Simulation Data example.

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

Junction Capacitance

The depletion region of a diode acts as a voltage-dependent capacitance that affects transient switching behavior. To model the junction capacitance, set the Modeling option parameter to Detailed with charge dynamics. This depletion-layer capacitance is distinct from the diffusion charge due to injected minority carriers, and both effects can be active at the same time. For more information about diffusion charge modeling, see Charge Dynamics.

You choose how to parameterize the junction capacitance by using the Parameterization parameter in the Capacitance settings. The Include fixed or zero junction capacitance option uses a constant capacitance value. The Use C-V curve data points and Use parameters CJO, VJ, M & FC options use a nonlinear SPICE depletion capacitance model to calculate a junction capacitance that depends on the junction voltage. The options differ only in how you supply the coefficients. Both options use the forward-bias capacitance coefficient FC. This table shows which other coefficients you need to provide and when to choose each option.

Parameterization Option	Description	Use Case
`Include fixed or zero junction capacitance`	The capacitance is fixed at the value you specify. Set the value to zero to disable capacitance modeling.	Capacitance is not critical or you only have a single-value estimate.
`Use C-V curve data points`	You specify three data points of the reverse voltage and the corresponding capacitance. The block estimates SPICE coefficients CJO, VJ, and M internally.	You have data sheet C-V curve values.
`Use parameters CJO, VJ, M & FC`	You specify the SPICE junction capacitance parameters CJO, VJ, and M directly.	You have SPICE parameters from a .model card or IBIS file.

When you set the Parameterization parameter to Use C-V curve data points, the block calculates CJO, VJ, and M using these equations,

$C J 0 = C_{1} {((V_{R 2} - V_{R 1}) / (V_{R 2} - V_{R 1} {(C_{2} / C_{1})}^{- 1 / M}))}^{M}$
$V J = - (- V_{R 2} {(C_{1} / C_{2})}^{- 1 / M} + V_{R 1}) / (1 - {(C_{1} / C_{2})}^{- 1 / M})$
$M = \log (C_{3} / C_{2}) / \log (V_{R 2} / V_{R 3})$

where:

V_R1, V_R2, and V_R3 are the values in the Reverse bias voltages [VR1 VR2 VR3] vector.
C₁, C₂, and C₃ are the values in the Corresponding capacitances [C1 C2 C3] vector.

The reverse bias voltages (defined as positive values) must satisfy V_R3 > V_R2 > V_R1. This means that the capacitances must satisfy C₁ > C₂ > C₃ as reverse bias widens the depletion region and hence reduces capacitance. Violating these inequalities results in an error. Voltages V_R2 and V_R3 should be well away from the junction potential VJ. Voltage V_R1 should be less than the junction potential VJ, with a typical value for V_R1 being 0.1 V.

For both the Use C-V curve data points and Use parameters CJO, VJ, M & FC options, the block defines the voltage-dependent junction capacitance in terms of the charge of junction capacitance Q_j as:

For V < FC·VJ:

$Q_{j} = C J 0 \cdot (V J / (M - 1)) \cdot ({(1 - V / V J)}^{1 - M} - 1)$
For V ≥ FC·VJ:

$Q_{j} = C J 0 \cdot F_{1} + (C J 0 / F_{2}) \cdot (F_{3} \cdot (V - F C \cdot V J) + 0.5 (M / V J) \cdot (V^{2} - {(F C \cdot V J)}^{2}))$

where:

$F_{1} = (V J / (1 - M)) \cdot (1 - {(1 - F C)}^{1 - M}))$
$F_{2} = {(1 - F C)}^{1 + M}))$
$F_{3} = 1 - F C \cdot (1 + M)$
V is the junction capacitance voltage.

These equations are the same as used in [2], except the block does not model the temperature dependence of VJ and FC.

Charge Dynamics

For applications such as commutation diodes, modeling diode charge dynamics is important. When a forward-biased diode has a reverse voltage applied across it, it takes time for the charge to dissipate and hence for the diode to turn off. The time taken for the diode to turn off is captured primarily by the transit time parameter. Once the diode is off, any remaining charge dissipates at a rate determined by the carrier lifetime.

This diffusion charge model is separate from the depletion-layer junction capacitance, which you can configure independently. For more information about junction capacitance modeling, see Junction Capacitance.

To model the charge dynamics, set the Modeling option parameter to Detailed with charge dynamics. If you only need to account for reverse recovery energy losses without modeling the underlying charge physics, set the Modeling option parameter to Ideal with thermal losses instead. For more information, see Reverse Recovery Losses.

The Diode block uses the model of Lauritzen and Ma [3] to capture these effects. These are the defining equations.

i = \frac{q_{E} - q_{M}}{T_{M}}

(1)

\frac{d q_{M}}{d t} + \frac{q_{M}}{τ} - \frac{q_{E} - q_{M}}{T_{M}} = 0

(2)

q_{E} = (τ + T_{M}) i

(3)

where:

i is the diode current.
q_E is the junction charge.
q_M is the total stored charge.
T_M is the transit time.
τ is the carrier lifetime.
v_D is the voltage across the diode.
v_F is the diode forward voltage.
R is the diode on resistance.
G is the diode off conductance.

This graphic shows a typical reverse-mode current characteristic for a diode device.

Current versus time plot showing reverse recovery. Current starts at forward current i_F and decreases at gradient a, reaching peak reverse current i_RM at time t_s, then recovering to i_RM/10. Reverse recovery time t_rr spans from the zero crossing to i_RM/10.

where:

i_RM is the peak reverse current.
i_F is the starting forward current when measuring i_RM.
a is the rate of change of current when measuring i_RM.
t_rr is the reverse recovery time.

Data sheets for diodes quote values for peak reverse current for an initial forward current and a steady rate of change of current. The data sheet might also provide values for reverse recovery time and total recovery charge.

How the Block Calculates T_M and τ

The block calculates transit time T_M and carrier lifetime τ based on the values you enter for the Charge Dynamics parameters. The block uses T_M and τ to solve the charge dynamics equations 1, 2, and 3.

During initial current drop in reverse mode, the diode is still on, and the rate of change of current is determined by an external test circuit.

First, the block uses equation 1 to perform this calculation.

i_{F} + a t = \frac{q_{E} - q_{M}}{T_{M}}

(4)

Then, it substitutes equation 4 into equation 2.

\frac{d q_{M}}{d t} + \frac{q_{M}}{τ} = i_{F} + a t

(5)

Then, it solves equation 5 for q_M,

q_{M} = i_{F} τ - a τ^{2} + \frac{k}{\exp (\frac{t}{τ})} + a τ t,

(6)

where k is a constant.

When t is zero, i = i_F and q_M = τi_F because the system is in steady state.

Substituting these relationships into equation 6 and solving the equation gives k = aτ².

Therefore,

q_{M} = i_{F} τ + a τ^{2} (\frac{1}{\exp (\frac{t}{τ})} - 1) + a τ t .

(7)

At time t = t_s, the current is i_RM and the junction charge q_E is zero.

The block substitutes these values into equation 1.

i_{R M} = \frac{- q_{M}}{T_{M}}

(8)

The block rearranges equation 8 to solve for q_M and substitutes the result into equation 7.

- T_{M} i_{R M} = i_{F} τ + a τ^{2} (\frac{1}{\exp (\frac{t_{s}}{τ})} - 1) + a τ t_{s}

(9)

Then, the block expresses time t_s in terms of i_RM, i_F, and a.

t_{s} = \frac{i_{R M} - i_{F}}{a}

(10)

Consider the diode recovery, that is, when t > t_s. The diode is reverse biased, and current and junction charge are effectively zero.

The current is defined by this equation.

i = i_{R M} exp[\frac{- (t - t_{s})}{τ_{r r}}],

(11)

where:

\frac{1}{τ_{r r}} = \frac{1}{τ} + \frac{1}{T_{M}} .

(12)

The block now relates the expression in equation 12 to the reverse recovery time t_rr.

When $t = \frac{i_{F}}{a} + t_{r r},$ the current is $\frac{i_{R M}}{10} .$

Therefore,

\exp (- \frac{t - t_{s}}{τ_{r r}}) = 0.1

(13)

and

t_{r r} = τ_{r r} \log (10) + \frac{i_{R M}}{a} .

(14)

The block uses equations 9 and 14 to calculate values for T_M and τ. The calculation uses an iterative scheme because of the exponential term in equation 9.

Alternatives to Specifying t_rr Directly

In addition to allowing you to specify reverse recovery time t_rr directly, the block supports three alternative parameterizations. The block can derive t_rr from either of these parameters:

Reverse recovery time stretch factor λ
Reverse recovery charge Q_rr, when the data sheet specifies this value instead of the reverse recovery time.
Reverse recovery energy E_rec, when the data sheet specifies this value instead of the reverse recovery time.

The relationship between reverse recovery time stretch factor λ and t_rr is expressed by the equation

$λ = \frac{t_{r r} a}{i_{R M}} .$

Reverse recovery time must be greater than $\frac{i_{R M}}{a}$ and a typical value is $3 (\frac{i_{R M}}{a}) .$

Therefore, a typical value for λ is 3. λ must be greater than 1.

Reverse recovery charge Q_rr is the integral over time of the reverse current from the point where the current goes negative until it decays back to zero.

The initial charge, to time t_s (as shown in the figure), is expressed by this equation:

Q_{s} = \frac{1}{2} (- i_{R M}) \frac{i_{R M}}{a} .

(15)

Integrating equation 11 gives the charge between times t_s and inf. This charge is equal to

$τ_{r r} i_{R M} .$

Therefore, total reverse recovery charge is given by this equation:

Q_{r r} = - \frac{i_{R M}^{2}}{2 a} - τ_{r r} i_{R M} .

(16)

Rearranging equation 16 to solve for τ_rr and substituting the result into equation 14 gives an equation that expresses t_rr in terms of Q_rr:

$t_{r r} = (\frac{Q_{r r}}{i_{R M}} + \frac{i_{R M}}{2 a}) \log (10) + \frac{i_{R M}}{a} .$

Alternatively, the block calculates τ_rr by using the reverse recovery energy, E_rec. This equation defines the diode voltage curve:

v_{d} = v_{R} - (v_{R} - v_{R M}) \exp (- (t - t_{1}) / τ_{r r}),

(17)

where

v_{R M} = v_{R} - i_{R M} (R - \frac{L}{τ_{r r}})

is the maximum diode reverse voltage.

If $\frac{L}{τ_{r r}} ≫ R$ , which is a common condition for the reverse recovery test circuit, the block calculates the maximum diode reverse voltage as:

$v_{R M} = v_{R} + i_{R M} \frac{L}{τ_{r r}} .$

Because the drop time value is small, the block assumes that the diode current drop is linear:

i_{F} + d i d t \cdot t = \frac{q_{E} - q_{M}}{T_{M}} .

(18)

Then, it substitutes equation 18 into equation 5:

\frac{d q_{M}}{d} + \frac{q_{M}}{τ} = i_{F} + d i d t \cdot t .

(19)

To obtain the total stored charge, it solves equation 19 :

q_{M} = i_{F} τ + d i d t \cdot τ^{2} (\frac{1}{\exp (\frac{t}{τ})} - 1) + d i d t \cdot τ t,

(20)

where didt is the gradient of the current.

When $t = t_{1} = \frac{i_{R M} - i_{F}}{d i d t}$ , the peak reverse current is:

i_{R M} = \frac{- q_{M}}{T_{M}} .

(21)

The block now substitutes equation 21 into equation 20:

\begin{array}{l} - i_{R M} T_{M} = i_{F} τ + d i d t \cdot τ^{2} (\exp (- \frac{i_{R M} - i_{F}}{d i d t \cdot τ}) - 1) + τ (i_{R M} - i_{F}) \\ - (T_{M} + τ) i_{R M} = d i d t \cdot τ^{2} (\exp (- \frac{i_{R M} - i_{F}}{d i d t \cdot τ}) - 1) \\ i_{R M} = F (d i d t, i_{F}, T_{M}, τ) . \end{array}

(22)

Finally, the block solves equation 22 to obtain the reverse recovery energy:

\begin{array}{l} E_{r e c} = \int_{t_{1}}^{t_{2}} i_{d} v_{d} d t \\ E_{r e c} = \frac{τ_{r r} i_{R M} (v_{R} + v_{R M})}{2} \\ E_{r e c} = \frac{i_{R M} (2 v_{R} τ_{r r} + i_{R M} L)}{2} . \end{array}

(23)

Charge dynamics with faults

When the device is faulted, the Diode block calculates the junction charge as

$q_{E} = (τ + T_{M}) i_{d i o d e},$

where:

i_diode is the diode current without the charge model.
q_E is the junction charge.
T_M is the transit time.
τ is the carrier lifetime.

This equation then defines the value of the diode current:

$\begin{array}{l} \frac{d q_{M}}{d t} + \frac{q_{M}}{τ} - \frac{q_{E} - q_{M}}{T_{M}} = 0 \\ i = \frac{q_{E} - q_{M}}{T_{M}} Q_{s c a l e} - (Q_{s c a l e} - 1) i_{d i o d e} \end{array}$

where:

i is the diode current.
q_M is the total stored charge.
Q_scale is the current value of the charge ratio.

Temperature Dependence

How the block models the effect of temperature on I-V characteristics depends on the diode model.

For a piecewise-linear I-V curve, there is no temperature dependence. The Forward voltage, On resistance, and Off conductance parameters have a fixed scalar value. Even when you enable the thermal port and the junction heats up, the I-V curve does not change.

For a tabulated I-V curve, the lookup table has a temperature dimension. You specify tabulated data for the Forward currents, If(Tj,Vf) or Forward voltages, Vf(Tj,If) parameters which are indexed by the Junction temperatures, Tj vector. The block evaluates the table at the device operating temperature. If you enable the thermal port, the block uses the live junction temperature from the thermal network. If you do not enable the thermal port, you specify a fixed device operating temperature.

The exponential diode model provides options to model how the diode current-voltage relationship depends on temperature during simulation. The block does not model the temperature dependence of the junction capacitance because it has a much smaller effect.

When including temperature dependence, the diode defining equation remains the same. The measurement temperature value, T_m1, is replaced with the simulation temperature, T_s. The saturation current, IS, becomes a function of temperature according to the following equation:

$I S = I S_{T s} = I S_{T m 1} \cdot {(T_{s} / T_{m 1})}^{X T I / N} \cdot \exp (- \frac{E G}{N k T_{s}} (1 - T_{s} / T_{m 1}))$

where:

T_m1 is the Measurement temperature parameter value. This parameter defines the operating temperature at which the electrical properties of the modeled device are equal to the corresponding block parameters values.
T_s is the simulation temperature.
IS_Tm1 is the saturation current at measurement temperature.
IS_Ts is the saturation current at simulation temperature. This is the saturation current value used in the standard diode equation when temperature dependence is modeled.
EG is the energy gap for the semiconductor type measured in joules (J). The value for silicon is usually taken to be 1.11 eV, where 1 eV is 1.602e-19.
XTI is the saturation current temperature exponent. This is usually set to 3.0 for pn-junction diodes, and 2.0 for Schottky barrier diodes.
N is the emission coefficient.
k is the Boltzmann constant (1.3806503e–23 J/K).

Appropriate values for XTI and EG depend on the type of diode and the semiconductor material. The block provides default values that capture approximate temperature behavior for common diode types.

In practice, you need to tune the values of XTI and EG to model the exact behavior of a particular diode. Some manufacturers quote these tuned values in a SPICE Netlist, and you can read off the appropriate values. Otherwise, you can determine improved estimates for EG by using a data-sheet-defined current-voltage data point at a higher temperature. The block provides a parameterization option for this. It also gives the option of specifying the saturation current at a higher temperature IS_Tm2 directly.

You can also tune the values of XTI and EG yourself, to match lab data for your particular device. You can use Simulink^® Design Optimization™ software to help tune the values for XTI and EG.

Caution

Device temperature behavior is also dependent on the emission coefficient. An inappropriate value for the emission coefficient can give incorrect temperature dependence, because saturation current is a function of the ratio of EG to N.

If you define a finite reverse breakdown voltage (BV), then the reverse breakdown temperature coefficient TCV (specified using the Reverse breakdown voltage temperature coefficient, dBV/dT parameter) modulates the value of the BV:

BV = BV_Ts = BV_Tm1 – TCV· (T_s – T_m1)

(24)

Modeling Thermal Effects

To model the effects of generated heat and device temperate, you need to enable the thermal port. Choose one of these options:

Set the Modeling option parameter to ideal with thermal losses.
Set the Modeling option parameter to Detailed with charge dynamics and select the Show thermal port parameter.

The block exposes the H port and creates an internal junction node J. Heat flows from the J node through a configurable internal thermal network. Some of the thermal energy accumulates in the block and some leaves through the H port.

You choose how to parameterize the internal thermal network by using the Thermal network parameter. You can specify the junction and case thermal parameters or use a Cauer model that you parameterize with Cauer or Foster Coefficients. You can also simulate the internal thermal network of the block externally. For more information about using thermal ports and the Thermal Port parameters, see Simulating Thermal Effects in Semiconductors.

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.

Note

To satisfy all your initial targets, do not set the priority to High for more initial targets than the total number of differential variables in the block equations.

If in the Capacitance section, you set Parameterization to Fixed or zero junction capacitance and Junction capacitance to 0, the total number of differential variables in the block equations is zero. Do not set the priority of any variables in the Initial Targets section to High.
If in the Capacitance section, you set Parameterization to Fixed or zero junction capacitance and you set the Junction capacitance parameter to a nonzero value, the total number of differential variables in the block equations is one. Set the priority to High for no more than one variable in the Initial Targets section.
If in the Capacitance section, you set Parameterization to Use C-V curve data points or Use parameters Cj0, VJ, M & FC, the total number of differential variables in the block equations is one. Set the priority to High for no more than one variable in the Initial Targets section.

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.

Parameterization

All three values of the Modeling option parameter support predefined parameterizations. Use this parameterization data to replicate the I-V curve for forward voltage from data sheets of specific suppliers. To load a predefined parameterization, double-click the Diode 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 judgment 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 Simscape Electrical Part Collection.

You can also use the ee_importDeviceParameters function to extract device parameters from an XML data sheet and import them into the block. The function configures the block with the Modeling option parameter set to Ideal with thermal losses. The XML file must be on the MATLAB^® path and must use a parameterization format supported by Hitachi, Infineon^®, or Wolfspeed.

When you set the Modeling option parameter to Detailed with charge dynamics, you can use the ee.spice.diodeSubcircuit2lookup function to generate lookup table data from a SPICE subcircuit. You can then use this data to parameterize the block. This function requires a SPICE simulation engine (SIMetrix or LTspice).

Faults

To model a fault in the Diode block, in the Faults section, click Add fault next to the fault that you want to model. For more information about fault modeling, see Fault Behavior Modeling and Fault Triggering.

The Diode block allows you to model three types of faults:

Open — Once the fault is triggered, the series resistance increases instantaneously. You can use this type of fault to model a diode that fails due to metallization burnout.
Short — Once the fault is triggered, the parallel conductance increases instantaneously. You can use this option to model a diode that fails due to punch-through.
Parameter shift — The block parameters shift over time starting from the moment that the fault is triggered. You can use this option to model a diode that fails due to aging.

The block can trigger fault events:

At a specific time.
When a current limit, a voltage limit, or a temperature limit is exceeded for longer than a specific time interval.

If you want to trigger a fault at a specific time, in the Fault Inspector window, set Trigger type to Timed. If you want to determine whether a system fails and, if so, when it fails, in the Fault Inspector window, set Trigger type to Behavioral.

If you select the behavioral trigger, the component fails as soon as one of the trigger conditions is true.

Parameter Shift Fault

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

$P a r a m e t e r (t) = P a r a m e t e r_{f a u l t e d} - (P a r a m e t e r_{f a u l t e d} - P a r a m e t e r_{u n f a u l t e d}) sech (\frac{t - t_{t h}}{τ}),$

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

Generate Derived Data Sheet

You can generate a derived data sheet for the Diode block that contains summary tables and characteristic plots similar to those that device manufacturers provide in their data sheets. A built-in MATLAB script calculates the block-level characteristics based on the parameter values in your model. Use derived data sheets to explore the effect of your parameter choices on device characteristics, help you select manufactured parts, or share your component-level design with others.

The derived data sheet for the Diode block includes these plots:

Forward current versus forward voltage at different temperatures
Reverse current versus reverse voltage at different temperatures
Reverse switching characteristics — Current versus time
Reverse recovery loss characteristics — Current versus reverse recovery loss

To generate a derived data sheet:

Open the MATLAB script by clicking the Open live script button next to the Derived data sheet parameter in the Utilities section of the block dialog box.
In the script that opens, provide values for any additional variables that the data sheet requires.
Click the Generate Data Sheet button in the script.

For more information about derived data sheets, see Generate Derived Data Sheets.

Plot Basic I-V Characteristics

You can plot the basic I-V characteristics of the Diode 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 data sheet, you can compare your plots to the data sheet 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 data sheets to help you decide.

To plot the basic I-V characteristics, set the Modeling option parameter to No thermal port and, in the Utilities section, click the Plot button next to the Basic characteristics parameter. (since R2026a) For more information about the Basic characteristics parameter, see Plot Basic I-V Characteristics of Semiconductor Blocks.

Examples

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

Optimize Liquid Cooling System of Inverter

Analyze the performance of a liquid cooling system for a three-phase inverter. To find the steady-state temperatures and losses, you first run detailed and reduced order models (ROM). Then you compute the optimal size of the heatsink that maximizes the inverter efficiency and minimizes the lifetime cost.

Open Live Script

Import Infineon XML Parts into Simscape IGBT and Diode Blocks

Automatically apply parameterizations from Infineon datasheets to tabulated IGBT (Ideal, Switching) and Diode blocks in Simscape™ Electrical™.

Since R2024a
Open Live Script

TVS Diode Parameterization

How to parameterize the Simscape™ Electrical™ diode to represent a Transient Voltage Suppression (TVS) diode. This example is for a TVS diode suited to protecting automotive electronics from voltage transients associated with turning off inductive loads. To view the data extracted from the datasheet, on the Modeling tab, in the Setup section, click Model Settings > Model Properties. On the Callbacks tab, click PreLoadFcn.

Open Model

Schottky Barrier Diode Characteristics

Generation of the current versus voltage curve for a Schottky barrier diode. Define the vector of temperatures for which to plot the characteristics by double clicking on the block labeled 'Define Temperatures for Tests'. Run the tests and plot the I-V curves by clicking in the model on the hyperlink 'plot curves'.

Open Model

Parameterize MOSFET and Diode Blocks from Wolfspeed Datasheets

Automatically apply parameterizations from Wolfspeed® datasheets to tabulated MOSFET (Ideal, Switching) and Diode blocks in Simscape™ Electrical™.

Since R2026a
Open Live Script

Assumptions and Limitations

When you select Use two I-V curve data points for the Parameterization parameter, choose a pair of voltages near the diode turn-on voltage. Typically, this is in the range from 0.05 to 1 V. Using values outside of this region may lead to numerical issues and poor estimates for IS and N.
The block does not account for temperature-dependent effects on the junction capacitance.
You might need to use nonzero ohmic resistance and junction capacitance values to prevent numerical simulation issues, but the simulation may run faster with these values set to zero.
If the value you specify for the Off state conductance parameter (Goff) is greater than the value of the on-state forward conductance for small forward voltages (gOnMin) that the block derives during the simulation, then the block uses the value of gOnMin to compute the reverse I-V characteristics of the diode instead of the value of the Off state conductance parameter. This assumption also applies to the faulted scenario.
The Diode block does not support energy accounting. If you try to get energy information for this block using the getEnergyInfo function, the function generates an error message.

Ports

Conserving

expand all

+ — Positive terminal
electrical

Electrical conserving port associated with the anode.

- — Negative terminal
electrical

Electrical conserving port associated with the cathode.

H — Thermal port
thermal

Thermal conserving port.

Dependencies

To enable this port, choose one of these options:

Set the Modeling option parameter to Ideal with thermal losses.
Set the Modeling option parameter to Detailed with charge dynamics and select the Show thermal port parameter.

Parameters

expand all

Modeling option — Level of model fidelity
`Ideal` (default) | `Ideal with thermal losses` | `Detailed with charge dynamics`

Level of model fidelity:

Ideal — The block uses a piecewise linear I-V curve. The block has no thermal port and does not model reverse recovery losses or charge dynamics.
Ideal with thermal losses — The block uses a piecewise linear or tabulated I-V curve. The block models reverse recovery losses as an energy loss at switching events and has an exposed thermal port.
Detailed with charge dynamics — The block uses a tabulated or exponential I-V curve. The block models charge dynamics to calculate reverse recovery losses as a continuous power loss and has an optional thermal port.

Part Repository

Part selection — Open Block Parameterization Manager
button

Use the Select part button to open the Block Parameterization Manager tool and view the available parts.

Active part — Active part
part ID

Active part associated with the block.

Dependencies

To enable this parameter, apply a part to the block by using the Block Parameterization Manager.

Status — Restore default part parameters
button

Click the Restore parameters button to restore the parameterization to the active part. The name of the parameter is Status: unmodified if the part uses the default properties for the parameter, and Status: modified if the parameters have been modified from the associated active part.

Dependencies

To enable this parameter, apply a part to the block by using the Block Parameterization Manager.

Manage — Clear part association
button

Use the Clear part association button to clear the active part associated with the block.

Dependencies

To enable this parameter, apply a part to the block by using the Block Parameterization Manager.

Main

Forward voltage — Voltage threshold for forward conduction
`0.6` `V` (default) | positive scalar

Minimum voltage that needs to be applied for the diode to become forward-biased.

Dependencies

To enable this parameter, choose one of these options:

Set the Modeling option parameter to Ideal.
Set the Modeling option parameter to Ideal with thermal losses and set the Diode model parameter to Piecewise linear.

On resistance — Resistance of the diode in forward conduction
`0.3` `Ohm` (default) | positive scalar

Resistance of the diode when it is forward biased.

Dependencies

To enable this parameter, choose one of these options:

Set the Modeling option parameter to Ideal.
Set the Modeling option parameter to Ideal with thermal losses and set the Diode model parameter to Piecewise linear.

Off conductance — Conductance of the diode in reverse bias
`1e-8` `1/Ohm` (default) | positive scalar

Conductance of the diode when it is reverse biased. The block uses this value to determine the reverse I-V characteristics when the Model Zener diode parameter is cleared.

Dependencies

To enable this parameter, choose one of these options:

Set the Modeling option parameter to Ideal.
Set the Modeling option parameter to Ideal with thermal losses and set the Diode model parameter to Piecewise linear.
Set the Modeling option parameter to Ideal with thermal losses, set the Diode model parameter to Tabulated I-V curve, and clear the Model Zener diode parameter.
Set the Modeling option parameter to Detailed with charge dynamics, set the Diode model parameter to Tabulated I-V curve, and clear the Model Zener diode parameter.

Number of series diodes — Number of diodes connected in series
`1` (default) | positive scalar integer

Number of diodes connected in series between the + and – block ports. The block does not model multiple diodes. Rather, each diode has all voltage-related quantities scaled by the factor that you specify.

Number of parallel diodes — Number of parallel diodes
`1` (default) | positive scalar integer

Number of parallel diodes, or number of parallel paths formed by series-connected diodes, between the + and – block ports. The block does not model multiple diodes. Rather, each diode has all current-related quantities scaled by the factor that you specify.

Show thermal port — Option to expose thermal port
`Off` (default) | `On`

Option to expose the thermal port of the block and model the effects of generated heat and device temperature.

Dependencies

To enable this parameter, set the Modeling option parameter to Detailed with charge dynamics.

Diode model — Type of I-V characteristic
`Piecewise linear` | `Tabulated I-V curve` | `Exponential`

Diode model. Choose one of these options:

Piecewise linear — Model the I-V curve as two linear regions separated by a forward voltage threshold. For more information, see Piecewise Linear Diode. This option is available only when you set the Modeling option parameter to Ideal with thermal losses. This is the default value for that modeling option.
Tabulated I-V curve — Model the I-V curve by interpolating between measured voltage-current data points. For more information, see Tabulated Diode.
Exponential — Model the diode using the Shockley diode equation. For more information, see Exponential Diode. This option is available only when you set the Modeling option parameter to Detailed with charge dynamics. This is the default value for that modeling option.

Dependencies

To enable this parameter, set the Modeling option parameter to Ideal with thermal losses or Detailed 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

To enable this parameter:

Set the Modeling option parameter to Ideal with thermal losses or Detailed with charge dynamics.
Set the Diode model parameter to Tabulated I-V curve.

Parameterization — Model parameterization
`Use two I-V curve data points` (default) | `Use parameters IS and N` | `Use an I-V data point and IS` | `Use an I-V data point and N`

Select one of the following methods for model parameterization:

Use two I-V curve data points — Specify measured data at two points on the diode I-V curve. This is the default method.
Use parameters IS and N — Specify saturation current and emission coefficient.
Use an I-V data point and IS — Specify measured data at a single point on the diode I-V curve in combination with the saturation current.
Use an I-V data point and N — Specify measured data at a single point on the diode I-V curve in combination with the emission coefficient.

Dependencies

To enable this parameter, set the Modeling option parameter to Detailed with charge dynamics and set the Diode model parameter to Exponential.

Currents [I1 I2] — Vector of current values at two points
`[.0137, .545]` `A` (default) | vector of positive scalars

Vector of the current values at the two points on the diode I-V curve that the block uses to calculate IS and N.

Dependencies

To enable this parameter:

Set the Modeling option parameter to Detailed with charge dynamics.
Set the Diode model parameter to Exponential.
Set the Parameterization parameter to Use two I-V curve data points.

Voltages [V1 V2] — Vector of voltage values at two points
`[.6, .7]` `V` (default) | vector of positive scalars

Vector of the voltage values at the two points on the diode I-V curve that the block uses to calculate IS and N.

Dependencies

To enable this parameter:

Set the Modeling option parameter to Detailed with charge dynamics.
Set the Diode model parameter to Exponential.
Set the Parameterization parameter to Use two I-V curve data points.

Saturation current, IS — Saturation current
`1e-12` `A` (default) | positive scalar

Magnitude of the current that the ideal diode equation approaches asymptotically for very large reverse bias levels.

Dependencies

To enable this parameter:

Set the Modeling option parameter to Detailed with charge dynamics.
Set the Diode model parameter to Exponential.
Set the Parameterization parameter to Use parameters IS and N or Use an I-V data point and IS.

Emission coefficient, N — Diode emission coefficient
`1` (default) | positive scalar

Diode emission coefficient or ideality factor.

Dependencies

To enable this parameter:

Set the Modeling option parameter to Detailed with charge dynamics.
Set the Diode model parameter to Exponential.
Set the Parameterization parameter to Use parameters IS and N or Use an I-V data point and N.

Current I1 — Current value
`0.0137` `A` (default) | positive scalar

Current value at the point on the diode I-V curve that the block uses for calculations. Depending on the Parameterization value, the block uses this parameter to calculate either N or IS.

Dependencies

To enable this parameter:

Set the Modeling option parameter to Detailed with charge dynamics.
Set the Diode model parameter to Exponential.
Set the Parameterization parameter to Use an I-V data point and IS or Use an I-V data point and N.

Voltage V1 — Voltage value
`0.6` `V` (default) | positive scalar

Voltage value at the point on the diode I-V curve that the block uses for calculations.

Dependencies

To enable this parameter:

Set the Modeling option parameter to Detailed with charge dynamics.
Set the Diode model parameter to Exponential.
Set the Parameterization parameter to Use an I-V data point and IS or Use an I-V data point and N.

Ohmic resistance, RS — Series connection resistance
`0` `Ohm` (default) | nonnegative scalar

Series diode connection resistance.

Dependencies

To enable this parameter, set the Modeling option parameter to Detailed with charge dynamics and set the Diode model parameter to Exponential.

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, 5.02, 8.35, 13.12]` `A` (default) | matrix of nonnegative scalars

Forward currents, tabulated by junction temperature and forward voltage. Each row corresponds to a junction temperature and must contain at least three nonnegative elements in ascending order. The zero point is optional (If(Tj,Vf) = 0A).

Dependencies

To enable this parameter:

Set the Modeling option parameter to Ideal with thermal losses or Detailed with charge dynamics.
Set the Diode model parameter to Tabulated I-V curve.
Set the Table type parameter 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) | matrix of nonnegative scalars

Forward voltages, tabulated by junction temperature and forward current. Each row corresponds to a junction temperature and must contain at least three nonnegative elements in ascending order. The zero point is optional (Vf(Tj,If) = 0V).

Dependencies

To enable this parameter:

Set the Modeling option parameter to Ideal with thermal losses or Detailed with charge dynamics.
Set the Diode model parameter to Tabulated I-V curve.
Set the Table type parameter to Table in Vf(Tj,If) form.

Junction temperatures, Tj — Vector of junction temperatures
`[25, 125]` `degC` (default) | vector

Vector of junction temperatures.

The values must increase monotonically.

If the size of the vector is equal to 1, the diode characteristics do not depend on the temperature.

Dependencies

To enable this parameter:

Set the Modeling option parameter to Ideal with thermal losses or Detailed with charge dynamics.
Set the Diode model parameter 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 nonnegative scalars

Vector of forward voltages. This parameter must be a vector of at least three nonnegative elements in ascending order. The zero point is optional (Vf = 0V).

Dependencies

To enable this parameter:

Set the Modeling option parameter to Ideal with thermal losses or Detailed with charge dynamics.
Set the Diode model parameter to Tabulated I-V curve.
Set the Table type parameter to Table in If(Tj,Vf) form.

Forward currents, If — Vector of forward currents
`[.1, .2, .5, 1, 2, 4, 7, 10]` `A` (default) | vector of nonnegative scalars

Vector of forward currents. This parameter must be a vector of at least three nonnegative elements in ascending order. The zero point is optional (If = 0A).

Dependencies

To enable this parameter:

Set the Modeling option parameter to Ideal with thermal losses or Detailed with charge dynamics.
Set the Diode model parameter to Tabulated I-V curve.
Set the Table type parameter to Table in Vf(Tj,If) form.

Breakdown

Model Zener diode — Option to model a Zener diode
`Off` (default) | `On`

Option to model a Zener diode.

Select this parameter to model a Zener diode that conducts in the forward and reverse biased directions. The block icon shows the electronic symbol for a Zener diode and you enable the parameters in the Breakdown settings. You must specify a finite value for the Reverse breakdown voltage parameter.

When you select this option and set the Diode model parameter to Tabulated I-V curve, you can model the reverse I-V characteristics by specifying the Reverse voltages, Vr(Tj,Ir), Reverse currents, Ir(Tj,Vr), Reverse voltages, Vr, and Reverse currents, Ir parameters.

Clear this parameter to model a standard diode that conducts in a single direction only. The block assumes that the reverse breakdown voltage is infinite, which effectively omits reverse breakdown from the model. The block icon shows the electronic symbol for a standard diode.

Zener resistance — Resistance of the diode in reverse breakdown
`0.3` `Ohm` (default) | positive scalar

Resistance of the diode when the voltage is less than the Reverse breakdown voltage value.

Dependencies

To enable this parameter, choose one of these options:

Set the Modeling option parameter to Ideal and select the Model Zener diode parameter.
Set the Modeling option parameter to Ideal with thermal losses, set the Diode model parameter to Piecewise linear, and select the Model Zener diode parameter.

Reverse breakdown voltage — Reverse breakdown voltage
`30` `V` (default) | positive scalar

Reverse voltage below which to model the rapid increase in conductance that occurs at diode breakdown.

Dependencies

To enable this parameter, choose one of these options:

Set the Modeling option parameter to Ideal and select the Model Zener diode parameter.
Set the Modeling option parameter to Ideal with thermal losses, set the Diode model parameter to Piecewise linear, and select the Model Zener diode parameter.
Set the Modeling option parameter to Detailed with charge dynamics, set the Diode model parameter to Exponential, and select the Model Zener diode parameter.

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) | matrix of nonnegative scalars

Reverse currents, tabulated by junction temperature and reverse voltage. Each row corresponds to a junction temperature and must contain at least three nonnegative elements in ascending order. The zero point is optional (Ir(Tj,Vr) = 0A).

Dependencies

To enable this parameter:

Set the Modeling option parameter to Ideal with thermal losses or Detailed with charge dynamics.
Set the Diode model parameter to Tabulated I-V curve.
Set the Table type parameter to Table in If(Tj,Vf) form.
Select the Model Zener diode parameter.

Reverse voltages, Vr — Vector of reverse voltages
`[10, 20, 40, 50, 70, 80, 100]` `V` (default) | vector of nonnegative scalars

Vector of reverse voltages. This parameter must be a vector of at least three nonnegative elements in ascending order. The zero point is optional (Vr = 0V).

Dependencies

To enable this parameter:

Set the Modeling option parameter to Ideal with thermal losses or Detailed with charge dynamics.
Set the Diode model parameter to Tabulated I-V curve.
Set the Table type parameter to Table in If(Tj,Vf) form.
Select the Model Zener diode parameter.

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) | matrix of nonnegative scalars

Reverse voltages, tabulated by junction temperature and reverse current. Each row corresponds to a junction temperature and must contain at least three nonnegative elements in ascending order. The zero point is optional (Vr(Tj,Ir) = 0V).

Dependencies

To enable this parameter:

Set the Modeling option parameter to Ideal with thermal losses or Detailed with charge dynamics.
Set the Diode model parameter to Tabulated I-V curve.
Set the Table type parameter to Table in Vf(Tj,If) form.
Select the Model Zener diode parameter.

Reverse currents, Ir — Vector of reverse currents
`[1e-06, 2e-06, 5e-06, 1e-05, 2e-05, 5e-05, .0001]` `A` (default) | vector of nonnegative scalars

Vector of reverse currents. This parameter must be a vector of at least three nonnegative elements in ascending order. The zero point is optional (Ir = 0A).

Dependencies

To enable this parameter:

Set the Modeling option parameter to Ideal with thermal losses or Detailed with charge dynamics.
Set the Diode model parameter to Tabulated I-V curve.
Set the Table type parameter to Table in Vf(Tj,If) form.
Select the Model Zener diode parameter.

Reverse Recovery Loss

To enable these parameters, set the Modeling option parameter to Ideal with thermal losses.

Reverse recovery loss model — Model for reverse recovery loss
`Fixed loss` (default) | `Tabulate loss with Tj and If` | `Tabulate loss with Tj, If, and Vrec`

Whether to model fixed or tabulated reverse recovery losses.

Reverse recovery loss — Reverse recovery energy loss per switching cycle
`0` `J` (default) | nonnegative scalar

Energy dissipated per reverse recovery 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 fixed recovery loss with current and voltage
`On` (default) | `Off`

Option to scale the fixed reverse recovery loss with the ratio of current and voltage at the time of switching to the current and voltage measurement conditions.

Dependencies

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

Forward current when measuring recovery loss, Irec — Forward current at which recovery loss is measured
`10` `A` (default) | positive scalar

Forward current at which the reverse recovery loss is measured.

Dependencies

To enable this parameter:

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

Turn-off voltage when measuring recovery loss, Vrec — Turn-off voltage at which recovery loss is measured
`10` `V` (default) | positive scalar

Turn-off voltage at which the reverse recovery loss is measured.

Dependencies

To enable this parameter, choose one of these options:

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

Filter time constant for voltage and current values — Time constant for filtering voltage and current
`1e-05` `s` (default) | positive scalar

Time constant for filtering voltage and current values used in scaling the reverse recovery loss.

Dependencies

To enable this parameter, choose one of these options:

Set the Reverse recovery loss model parameter to Fixed loss and select the Scale reverse recovery loss with current and voltage parameter.
Set the Reverse recovery loss model parameter to Tabulate loss with Tj and If.
Set the Reverse recovery loss model parameter to Tabulate loss with Tj, If, and Vrec.

Reverse recovery loss table, Erec(Tj, If) — 2-D table of recovery loss versus temperature and current
`zeros(2,3)` `J` (default) | matrix of nonnegative scalars

Matrix of reverse recovery energy loss values, tabulated by junction temperature and forward current.

Dependencies

To enable this parameter, set the Reverse recovery loss model parameter to Tabulate loss with Tj and If.

Temperature vector for recovery loss table, Tj — Vector of junction temperatures for recovery loss table
`[25, 125]` `degC` (default) | vector

Vector of junction temperatures at which the reverse recovery loss is tabulated.

The values must increase monotonically.

Dependencies

To enable this parameter, set the Reverse recovery loss model parameter to Tabulate loss with Tj and If or Tabulate loss with Tj, If, and Vrec.

Forward current vector for reverse recovery loss table, If — Vector of forward currents for recovery loss table
`[0.1, 1, 10]` `A` (default) | vector of nonnegative scalars

Vector of forward currents at which the reverse recovery loss is tabulated.

The values must increase monotonically.

Dependencies

To enable this parameter, set the Reverse recovery loss model parameter to Tabulate loss with Tj and If or Tabulate loss with Tj, If, and Vrec.

Reverse recovery loss table, Erec(Tj, If, Vrec) — 3-D table of recovery loss versus temperature, current, and voltage
`zeros(2,3,2)` `J` (default) | 3-D array of nonnegative scalars

Matrix of reverse recovery energy loss values, tabulated by junction temperature, forward current, and turn-off voltage.

Dependencies

To enable this parameter, set the Reverse recovery loss model parameter to Tabulate loss with Tj, If, and Vrec.

Turn-off voltage vector for reverse recovery loss table, Vrec — Vector of turn-off voltages for 3-D recovery loss table
`[0, 100]` `V` (default) | vector of nonnegative scalars

Vector of turn-off voltages at which the reverse recovery loss is tabulated.

The values must increase monotonically.

Dependencies

To enable this parameter, set the Reverse recovery loss model parameter to Tabulate loss with Tj, If, and Vrec.

Capacitance

To enable these parameters, set the Modeling option parameter to Detailed with charge dynamics.

Parameterization — Modeling junction capacitance
`Fixed or zero junction capacitance` (default) | `Use C-V curve data points` | `Use parameters CJ0, VJ, M & FC`

Method for modeling the junction capacitance:

Fixed or zero junction capacitance — Model the junction capacitance as a fixed value.
Use C-V curve data points — Specify measured data at three points on the diode C-V curve.
Use parameters CJ0, VJ, M & FC — Specify zero-bias junction capacitance, junction potential, grading coefficient, and forward-bias depletion capacitance coefficient.

Junction capacitance — Fixed capacitance across the diode junction
`0` `pF` (default) | nonnegative scalar

Fixed junction capacitance value.

Dependencies

To enable this parameter, set the Parameterization parameter to Fixed or zero junction capacitance.

Reverse bias voltages [VR1 VR2 VR3] — Vector of reverse bias voltage values
`[.1, 10, 100]` `V` (default) | vector of three nonnegative scalars

Vector of the reverse bias voltage values at the three points on the diode C-V curve that the block uses to calculate CJ0, VJ, and M.

Dependencies

To enable this parameter, set the Parameterization parameter to Use C-V curve data points.

Corresponding capacitances [C1 C2 C3] — Vector of capacitance values
`[3.5, 1, .4]` `pF` (default) | vector of nonnegative scalars

Vector of the capacitance values at the three points on the diode C-V curve that the block uses to calculate CJ0, VJ, and M.

Dependencies

To enable this parameter, set the Parameterization parameter to Use C-V curve data points.

Capacitance coefficient, FC — Capacitance coefficient
`0.5` (default) | positive scalar

Fitting coefficient that quantifies the decrease of the depletion capacitance with applied voltage.

Dependencies

To enable this parameter, set the Parameterization parameter to Use C-V curve data points or Use parameters CJ0, VJ, M & FC.

Zero-bias junction capacitance, CJ0 — Zero-bias junction capacitance
`5` `pF` (default) | positive scalar

Value of the capacitance placed in parallel with the conduction current term.

Dependencies

To enable this parameter, set the Parameterization parameter to Use parameters CJ0, VJ, M & FC.

Junction potential, VJ — Junction potential
`1` `V` (default) | positive scalar

Junction potential.

Dependencies

To enable this parameter, set the Parameterization parameter to Use parameters CJ0, VJ, M & FC.

Grading coefficient, M — Grading coefficient
`0.5` (default) | positive scalar

Grading coefficient.

Dependencies

To enable this parameter, set the Parameterization parameter to Use parameters CJ0, VJ, M & FC.

Charge dynamics — Charge dynamics parameterization
`Do not model charge dynamics` (default) | `Use peak reverse current and stretch factor` | `Use peak reverse current and reverse recovery time` | `Use peak reverse current and reverse recovery charge` | `Use peak reverse current and reverse recovery energy` | `Use transit time and carrier lifetime`

Select one of the following methods for charge dynamics parameterization:

Do not model charge dynamics — Do not include charge dynamics modeling. This is the default method.
Use peak reverse current and stretch factor — Model charge dynamics by providing values for peak reverse current i_RM and stretch factor λ plus information on the initial forward current and rate of change of current used in the test circuit when measuring i_RM and t_rr.
Use peak reverse current and reverse recovery time — Model charge dynamics by providing values for peak reverse current i_RM and reverse recovery time t_rr plus information on the initial forward current and rate of change of current used in the test circuit when measuring i_RM and t_rr. Use this option if the manufacturer data sheet does not provide values for transit time TT and carrier lifetime τ.
Use peak reverse current and reverse recovery charge — Model charge dynamics by providing values for peak reverse current i_RM and reverse recovery charge Qrr plus information on the initial forward current and rate of change of current used in the test circuit when measuring i_RM and t_rr.
Use peak reverse current and reverse recovery energy — Model charge dynamics by providing values for peak reverse current i_RM and reverse recovery energy Erec plus information on the initial forward current and rate of change of current used in the test circuit when measuring i_RM.
Use transit time and carrier lifetime — Model charge dynamics by providing values for transit time TT and carrier lifetime τ.

Peak reverse current, iRM — Peak reverse current
`-7.15` `A` (default) | negative scalar

Peak reverse current measured by an external test circuit. This value must be less than zero.

Dependencies

To enable this parameter, set the Charge dynamics parameter to Use peak reverse current and stretch factor, Use peak reverse current and reverse recovery time, Use peak reverse current and reverse recovery charge, or Use peak reverse current and reverse recovery energy.

Initial forward current when measuring iRM — Initial forward current when measuring iRM
`4` `A` (default) | positive scalar

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

Dependencies

Rate of change of current when measuring iRM — Rate of change of current when measuring iRM
`-750` `A/μs` (default) | negative scalar

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

Dependencies

Reverse recovery time stretch factor — Reverse recovery time stretch factor
`3` (default) | scalar greater than 1

Value that the block uses to calculate Reverse recovery time, trr. This value must be greater than 1. The default value is 3.

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

To enable this parameter, set the Charge dynamics parameter to Use peak reverse current and stretch factor.

Reverse recovery time, trr — Reverse recovery time
`115` `ns` (default) | positive scalar

Time between the point where the current initially goes to zero when the diode turns off, and the point where the current falls to less than ten percent of the peak reverse current.

The value of the 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

To enable this parameter, set the Charge dynamics parameter to Use peak reverse current and reverse recovery time.

Reverse recovery charge, Qrr — Reverse recovery charge
`150` `nA*s` (default) | positive scalar

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 $- \frac{i^{2}_{R M}}{2 a},$

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

To enable this parameter, set the Charge dynamics parameter to Use peak reverse current and reverse recovery charge.

Diode turn-off voltage when measuring Erec — Diode turn-off voltage when measuring Erec
`-600` `V` (default) | negative scalar

Voltage between the diode in steady-state.

Dependencies

To enable this parameter, set the Charge dynamics parameter to Use peak reverse current and reverse recovery energy.

Stray inductance when measuring Erec — Stray inductance when measuring Erec
`150` `nH` (default) | nonnegative scalar

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

Dependencies

To enable this parameter, set the Charge dynamics parameter to Use peak reverse current and reverse recovery energy.

Reverse recovery energy, Erec — Reverse recovery energy
`0.03` `J` (default) | positive scalar

Total switching losses due to the diode reverse recovery.

Dependencies

To enable this parameter, set the Charge dynamics parameter to Use peak reverse current and reverse recovery energy.

Transit time, TT — Transit time
`50` `ns` (default) | positive scalar

Measure of how long it takes carriers to cross the diode junction.

Dependencies

To enable this parameter, set the Charge dynamics parameter to Use transit time and carrier lifetime.

Carrier lifetime, tau — Carrier lifetime
`100` `ns` (default) | positive scalar

Measure of how long it takes for the carriers to dissipate once the diode is no longer conducting. The default value is 100 ns.

Dependencies

To enable this parameter, set the Charge dynamics parameter to Use transit time and carrier lifetime.

Temperature Dependence

To enable these parameters, set the Modeling option parameter to Detailed with charge dynamics.

Parameterization — Temperature dependence parameterization
`None - Use characteristics at parameter measurement temperature` (default) | `Use an I-V data point at second measurement temperature` | `Specify saturation current at second measurement temperature` | `Specify the energy gap, EG`

Select one of the following methods for temperature dependence parameterization:

None - Use characteristics at parameter measurement temperature — Temperature dependence is not modeled, or the model is simulated at the measurement temperature T_m1 (as specified by the Measurement temperature parameter). This is the default method.
Use an I-V data point at second measurement temperature — If you select this option, you specify a second measurement temperature T_m2, and the current and voltage values at this temperature. The model uses these values, along with the parameter values at the first measurement temperature T_m1, to calculate the energy gap value.
Specify saturation current at second measurement temperature — If you select this option, you specify a second measurement temperature T_m2, and saturation current value at this temperature. The model uses these values, along with the parameter values at the first measurement temperature T_m1, to calculate the energy gap value.
Specify the energy gap, EG — Specify the energy gap value directly.

Dependencies

To enable this parameter, set the Diode model parameter to Exponential.

Measurement temperature — Measurement temperature
`25` `degC` (default) | scalar

Temperature T_m1 at which IS or the I-V curve was measured.

The value must be greater than 0 K.

Dependencies

To enable this parameter, set the Diode model parameter to Exponential.

Current I1 at second measurement temperature — Current I1 at second measurement temperature
`0.245` `A` (default) | positive scalar

Specify the diode current I1 value when the voltage is V1 at the second measurement temperature.

Dependencies

To enable this parameter, set the Parameterization parameter to Use an I-V data point at second measurement temperature.

Voltage V1 at second measurement temperature — Voltage V1 at second measurement temperature
`0.5` `V` (default) | positive scalar

Specify the diode voltage V1 value when the current is I1 at the second measurement temperature.

Dependencies

To enable this parameter, set the Parameterization parameter to Use an I-V data point at second measurement temperature.

Saturation current, IS, at second measurement temperature — Saturation current, IS, at second measurement temperature
`1.25e-7` `A` (default) | positive scalar

Specify the saturation current IS value at the second measurement temperature.

Dependencies

To enable this parameter, set the Parameterization parameter to Specify saturation current at second measurement temperature.

Second measurement temperature — Second measurement temperature
`125` `degC` (default) | scalar

Specify the value for the second measurement temperature.

The value must be greater than 0 K and must not equal the first measurement temperature.

Dependencies

To enable this parameter, set the Parameterization parameter to Use an I-V data point at second measurement temperature or Specify saturation current at second measurement temperature.

Energy gap parameterization — Energy gap parameterization
`Use nominal value for silicon (EG=1.11eV)` (default) | `Use nominal value for 4H-SiC silicon carbide (EG=3.23eV)` | `Use nominal value for 6H-SiC silicon carbide (EG=3.00eV)` | `Use nominal value for germanium (EG=0.67eV)` | `Use nominal value for gallium arsenide (EG=1.43eV)` | `Use nominal value for selenium (EG=1.74eV)` | `Use nominal value for Schottky barrier diodes (EG=0.69eV)` | `Specify a custom value`

Select a value for the energy gap from a list of predetermined options, or specify a custom value:

Use nominal value for silicon (EG=1.11eV) — This is the default.
Use nominal value for 4H-SiC silicon carbide (EG=3.23eV)
Use nominal value for 6H-SiC silicon carbide (EG=3.00eV)
Use nominal value for germanium (EG=0.67eV)
Use nominal value for gallium arsenide (EG=1.43eV)
Use nominal value for selenium (EG=1.74eV)
Use nominal value for Schottky barrier diodes (EG=0.69eV)
Specify a custom value — If you select this option, the Energy gap, EG parameter appears in the dialog box, to let you specify a custom value for EG.

Dependencies

To enable this parameter, set the Parameterization parameter to Specify the energy gap, EG.

Energy gap, EG — Energy gap
`1.11` `eV` (default) | scalar

Specify a custom value for the energy gap, EG.

Dependencies

To enable this parameter, set the Energy gap parameterization parameter to Specify a custom value.

Saturation current temperature exponent parameterization — Saturation current temperature exponent parameterization
`Use nominal value for pn-junction diode (XTI=3)` (default) | `Use nominal value for Schottky barrier diode (XTI=2)` | `Specify a custom value`

Select one of the following options to specify the saturation current temperature exponent value:

Use nominal value for pn-junction diode (XTI=3) — This is the default.
Use nominal value for Schottky barrier diode (XTI=2)
Specify a custom value — If you select this option, the Saturation current temperature exponent, XTI parameter appears in the dialog box, to let you specify a custom value for XTI.

Dependencies

To enable this parameter, set the Parameterization parameter to Use an I-V data point at second measurement temperature, Specify saturation current at second measurement temperature, or Specify the energy gap, EG.

Saturation current temperature exponent, XTI — Saturation current temperature exponent
`3` (default) | scalar

Specify a custom value for the saturation current temperature exponent, XTI.

Dependencies

To enable this parameter:

Set the Parameterization parameter to Use an I-V data point at second measurement temperature, Specify saturation current at second measurement temperature, or Specify the energy gap, EG.
Set the Saturation current temperature exponent parameterization parameter to Specify a custom value.

Reverse breakdown voltage temperature coefficient, dBV/dT — Reverse breakdown voltage temperature coefficient
`0` `V/K` (default) | scalar

Modulate the reverse breakdown voltage BV. If you define the reverse breakdown voltage BV as a positive quantity, a positive value for TCV implies that the magnitude of the reverse breakdown voltage decreases with temperature.

Dependencies

To enable this parameter:

Select the Model Zener diode parameter.
Set the Parameterization parameter to Use an I-V data point at second measurement temperature, Specify saturation current at second measurement temperature, or Specify the energy gap, EG.

Device simulation temperature — Device simulation temperature
`25` `degC` (default) | scalar

Specify the value for the temperature T_s, at which the device is to be simulated.

Dependencies

To enable this parameter, clear the Show thermal port parameter and choose one of these options:

Set the Diode model parameter to Exponential and set the Parameterization parameter to Use an I-V data point at second measurement temperature, Specify saturation current at second measurement temperature, or Specify the energy gap, EG.
Set the Diode model parameter to Tabulated I-V curve.

Faults

Diode fault — Option to model fault in diode
`Add fault` (default)

Option to model a fault in the Diode block.

To add a fault, click the Add fault hyperlink.

Failure mode — Failure category
`Open` (default) | `Short` | `Parameter shift`

Specify the failure mode of the Diode block:

Open — Once the fault is triggered, the series resistance increases instantaneously. You can use this type of fault to model a diode that fails due to metallization burnout.
Short — Once the fault is triggered, the parallel conductance increases instantaneously. You can use this option to model a diode that fails due to punch-through.
Parameter shift — The block parameters change over time starting from the moment that the fault is triggered. You can use this option to model a diode that fails due to aging.

Dependencies

To enable this parameter, add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.

After you create the fault, you can change the properties in the Fault Inspector window. When you open a block that has a fault, the Open Fault Inspector hyperlink appears instead of the Add fault hyperlink. For an example that shows how to include faults, see Analyze a DC Armature Winding Fault.

Fault transition time constant — Fault transition time constant
`1e-3` `s` (default) | positive scalar

Time constant for transitioning to faulted state.

Dependencies

To enable this parameter, add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.

Faulted series resistance — Faulted series resistance
`1000` `Ohm` (default) | finite nonnegative scalar

Series resistance in faulted state.

Dependencies

To enable this parameter:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
Set the Failure mode parameter to Open.

Faulted parallel conductance — Faulted parallel conductance
`1000` `1/Ohm` (default) | finite nonnegative scalar

Parallel conductance in faulted state.

Dependencies

To enable this parameter:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
Set the Failure mode parameter to Short.

Faulted forward voltage — Faulted forward voltage
`0.6` `V` (default) | positive scalar

Forward voltage in faulted state.

Dependencies

To enable this parameter:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
Set the Failure mode parameter to Parameter shift.
Choose one of these options:
- Set the Modeling option parameter to Ideal.
- Set the Modeling option parameter to Ideal with thermal losses and set the Diode model parameter to Piecewise linear.

Faulted on resistance — Faulted on resistance
`0.3` `Ohm` (default) | positive scalar

On resistance in faulted state.

Dependencies

To enable this parameter:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
Set the Failure mode parameter to Parameter shift.
Choose one of these options:
- Set the Modeling option parameter to Ideal.
- Set the Modeling option parameter to Ideal with thermal losses and set the Diode model parameter to Piecewise linear.

Faulted off conductance — Faulted off conductance
`1e-8` `S` (default) | positive scalar

Off conductance in faulted state.

Dependencies

To enable this parameter:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
Set the Failure mode parameter to Parameter shift.
Choose one of these options:
- Set the Modeling option parameter to Ideal.
- Set the Modeling option parameter to Ideal with thermal losses and set the Diode model parameter to Piecewise linear.
- Set the Modeling option parameter to Ideal with thermal losses or Detailed with charge dynamics, set the Diode model parameter to Tabulated I-V curve, and clear the Model Zener diode parameter.

Faulted zener resistance — Faulted Zener resistance
`0.3` `Ohm` (default) | positive scalar

Zener resistance in faulted state.

Dependencies

To enable this parameter:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
Set the Failure mode parameter to Parameter shift.
Choose one of these options:
- Set the Modeling option parameter to Ideal.
- Set the Modeling option parameter to Ideal with thermal losses and set the Diode model parameter to Piecewise linear.

Faulted reverse breakdown voltage — Faulted reverse breakdown voltage
`inf` `V` (default) | positive scalar

Reverse breakdown voltage in faulted state.

Dependencies

To enable this parameter:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
Set the Failure mode parameter to Parameter shift.
Choose one of these options:
- Set the Modeling option parameter to Ideal.
- Set the Modeling option parameter to Ideal with thermal losses and set the Diode model parameter to Piecewise linear.
- Set the Modeling option parameter to Detailed with charge dynamics and set the Diode model parameter to Exponential.

Faulted currents, [I1 I2] — Faulted currents
`[.0137, .545]` `A` (default) | 2-D vector of positive scalars

I1 and I2 currents in faulted state.

Dependencies

To enable this parameter:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
Set the Diode model parameter to Exponential.
Set the Parameterization parameter, in the Main settings, to Use two I-V curve data points.
Set the Failure mode parameter to Parameter shift.

Faulted voltages, [V1 V2] — Faulted voltages
`[.6, .7]` `V` (default) | 2-D vector of positive scalars

V1 and V2 voltages in faulted state.

Dependencies

To enable this parameter:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
Set the Diode model parameter to Exponential.
Set the Parameterization parameter, in the Main settings, to Use two I-V curve data points.
Set the Failure mode parameter to Parameter shift.

Faulted ohmic resistance, RS — Faulted voltages
`0` `Ohm` (default) | nonnegative scalar

Ohmic resistance in faulted state.

Dependencies

To enable this parameter:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
Set the Diode model parameter to Exponential.
Set the Failure mode parameter to Parameter shift.

Faulted saturation current, IS — Faulted saturation current
`1e-12` `A` (default) | positive scalar

Saturation current in faulted state.

Dependencies

To enable this parameter:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
Set the Diode model parameter to Exponential.
Set the Parameterization parameter, in the Main settings, to Use parameters IS and N or Use an I-V data point and IS.
Set the Failure mode parameter to Parameter shift.

Faulted emission coefficient, N — Faulted emission coefficient
`1` (default) | positive scalar

Emission coefficient in faulted state.

Dependencies

To enable this parameter:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
Set the Diode model parameter to Exponential.
Set the Parameterization parameter, in the Main settings, to Use parameters IS and N or Use an I-V data point and N.
Set the Failure mode parameter to Parameter shift.

Faulted current, I1 — Faulted current
`0.0137` `A` (default) | positive scalar

Current in faulted state.

Dependencies

To enable this parameter:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
Set the Diode model parameter to Exponential.
Set the Parameterization parameter, in the Main settings, to Use an I-V data point and IS or Use an I-V data point and N.
Set the Failure mode parameter to Parameter shift.

Faulted voltage, V1 — Faulted voltage
`0.6` `V` (default) | positive scalar

Voltage in faulted state.

Dependencies

To enable this parameter:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
Set the Diode model parameter to Exponential.
Set the Parameterization parameter, in the Main settings, to Use an I-V data point and IS or Use an I-V data point and N.
Set the Failure mode parameter to Parameter shift.

Faulted forward currents, If(Tj,Vf) — Faulted 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) | matrix of nonnegative scalars

Forward currents, If(Tj,Vf), in faulted state. This parameter must be a vector of at least three nonnegative elements in ascending order. The zero point is optional (Ir(Tj,Vr) = 0A).

Dependencies

To enable this parameter:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
Set the Diode model parameter to Tabulated I-V curve.
Set the Table type parameter to Table in If(Tj,Vf) form.
Set the Failure mode parameter to Parameter shift.

Faulted forward voltages, Vf — Faulted forward voltages
`[.5, .7, .9, 1.3, 1.7, 2.1, 2.5]` `V` (default) | vector of nonnegative scalars

Forward voltages, Vf, in faulted state. This parameter must be a vector of at least three nonnegative elements in ascending order. The zero point is optional (Vf = 0 V).

Dependencies

To enable this parameter:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
Set the Diode model parameter to Tabulated I-V curve.
Set the Table type parameter to Table in If(Tj,Vf) form.
Set the Failure mode parameter to Parameter shift.

Faulted reverse currents, Ir(Tj,Vr) — Faulted 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) | matrix of nonnegative scalars

Reverse currents, Ir(Tj,Vr), in faulted state. This parameter must be a vector of at least three nonnegative elements in ascending order. The zero point is optional (Ir(Tj,Vr) = 0A).

Dependencies

To enable this parameter:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
Set the Diode model parameter to Tabulated I-V curve.
Set the Table type parameter to Table in If(Tj,Vf) form.
Select the Model Zener diode parameter.
Set the Failure mode parameter to Parameter shift.

Faulted reverse voltages, Vr — Faulted reverse voltages
`[1, 2, 4, 5, 7, 8, 10]` `V` (default) | vector of nonnegative scalars

Reverse voltages, Vr, in faulted state. This parameter must be a vector of at least three nonnegative elements in ascending order. The zero point is optional (Vr = 0V).

Dependencies

To enable this parameter:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
Set the Diode model parameter to Tabulated I-V curve.
Set the Table type parameter to Table in If(Tj,Vf) form.
Select the Model Zener diode parameter.
Set the Failure mode parameter to Parameter shift.

Faulted forward voltages, Vf(Tj,If) — Faulted 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) | matrix of nonnegative scalars

Forward voltages, Vf(Tj,If), in faulted state. This parameter must be a vector of at least three nonnegative elements in ascending order. The zero point is optional (Vf(Tj,If) = 0V).

Dependencies

To enable this parameter:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
Set the Diode model parameter to Tabulated I-V curve.
Set the Table type parameter to Table in Vf(Tj,If) form.
Set the Failure mode parameter to Parameter shift.

Faulted forward currents, If — Faulted forward currents
`[.1, .2, .5, 1, 2, 4, 7, 10]` `A` (default) | vector of nonnegative scalars

Forward currents, If, in faulted state. This parameter must be a vector of at least three nonnegative elements in ascending order. The zero point is optional (If = 0A).

Dependencies

To enable this parameter:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
Set the Diode model parameter to Tabulated I-V curve.
Set the Table type parameter to Table in Vf(Tj,If) form.
Set the Failure mode parameter to Parameter shift.

Faulted reverse voltages, Vr(Tj,Ir) — Faulted reverse voltages
`[1, 10, 20, 25, 30, 32.5, 35; 1, 5, 10, 20, 25, 30, 32]` `V` (default) | matrix of nonnegative scalars

Reverse voltages, Vr(Tj,Ir), in faulted state. This parameter must be a vector of at least three nonnegative elements in ascending order. The zero point is optional (Vr(Tj,ir) = 0V).

Dependencies

To enable this parameter:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
Set the Diode model parameter to Tabulated I-V curve.
Set the Table type parameter to Table in Vf(Tj,If) form.
Select the Model Zener diode parameter.
Set the Failure mode parameter to Parameter shift.

Faulted reverse currents, Ir — Faulted reverse currents
`[1e-06, 2e-06, 5e-06, 1e-05, 2e-05, 5e-05, .0001]` `A` (default) | vector of nonnegative scalars

Reverse currents, Ir, in faulted state. This parameter must be a vector of at least three nonnegative elements in ascending order. The zero point is optional (Ir = 0 A).

Dependencies

To enable this parameter:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
Set the Diode model parameter to Tabulated I-V curve.
Set the Table type parameter to Table in Vf(Tj,If) form.
Select the Model Zener diode parameter.
Set the Failure mode parameter to Parameter shift.

Faulted capacitance and charge as percentage of unfaulted — Faulted capacitance and charge as percentage of unfaulted
`100` (default) | finite positive scalar

Capacitance and charge in faulted state as percentage of unfaulted.

Dependencies

To enable this parameter:

Set the Modeling option parameter to Detailed with charge dynamics.
Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.

Trigger type — Trigger type
`Always on` (default) | `Timed` | `Behavioral` | `Additional triggers` | `Conditional` | `Manual`

Trigger type, specified as one of these options:

Always On — The fault injects at the start of the simulation.
Timed — The fault injects when the simulation time reaches the value you specify for the Trigger fault at time parameter.
Behavioral — The fault injects as a result of fault parameter values during simulation. Setting Trigger type to Behavioral enables block parameters that define the failure conditions.
Additional triggers — The fault injects as a result of additional triggers not available in the block dialog box. Select this option and click the Open fault properties hyperlink to set the Trigger type to one of these values in the Property Inspector:
- Conditional — The fault injects as a result of a condition that reflects a behavior associated with a signal. Conditionals evaluate the Boolean expression in the Condition parameter at each time step. The block enters the faulted state when the trigger condition becomes true for the first time and remains in the faulted state for the rest of the simulation. To learn more, see Create and Manage Conditionals.
- Manual — The fault injects or clears when you toggle the status in the Fault Dashboard pane. To learn more, see Manually Trigger Faults in Models.

Dependencies

To enable this parameter, add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.

Trigger fault at time — Time before entering faulted state
`0` `s` (default) | nonnegative scalar

Simulation time at which the block enters the faulted state.

Dependencies

To enable this parameter, add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter and set the Trigger type parameter to Timed.

Maximum permissible reverse voltage — Maximum permissible reverse voltage
`inf` `V` (default) | positive scalar

Maximum reverse voltage above which the fault triggers.

Dependencies

To enable this parameter, set Trigger Type to Behavioral.

Number of events to fail when exceeding voltage — Number of overvoltage events before failure
`1` (default) | positive scalar integer

Number of times the diode must exceed the reverse voltage threshold before a fault triggers.

Dependencies

To enable this parameter, set Trigger Type to Behavioral.

Maximum permissible current — Current threshold to fault transition
`inf` `A` (default) | positive scalar

Current threshold to a fault transition. If the current exceeds this value for longer than the Time to fail when exceeding current parameter value, then the block enters the faulted state.

Dependencies

To enable this parameter, set Trigger Type to Behavioral.

Time to fail when exceeding current — Maximum length of time the current exceeds the threshold
`1` `s` (default) | positive scalar

Maximum length of time that the current can exceed the maximum permissible value without triggering the fault.

Dependencies

To enable this parameter, set Trigger Type to Behavioral.

Maximum diode recovery, dV/dt — Diode recovery threshold
`inf` `V/s` (default) | positive scalar

Maximum diode recovery.

Dependencies

To enable this parameter:

Set the Modeling option parameter to Detailed with charge dynamics.
Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
Set the Trigger Type parameter to Behavioral.

Maximum permissible temperature — Temperature threshold to fault transition
`inf` `K` (default) | positive scalar

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:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
In the Fault Inspector window, set Trigger Type to Behavioral.
Choose one of these options:
- Set the Modeling option parameter to Ideal with thermal losses.
- Set the Modeling option parameter to Detailed with charge dynamics and select the Show thermal port parameter.

This parameter appears in the Trigger section of the Fault Inspector window.

Time to fail when exceeding temperature — Time to fail when exceeding temperature
`1` `s` (default) | positive scalar

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

Dependencies

To enable this parameter:

Add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter.
In the Fault Inspector window, set Trigger Type to Behavioral.
Choose one of these options:
- Set the Modeling option parameter to Ideal with thermal losses.
- Set the Modeling option parameter to Detailed with charge dynamics and select the Show thermal port parameter.

This parameter appears in the Trigger section of the Fault Inspector window.

Trigger configuration — Option to enable additional trigger types
`Open fault properties`

Option to enable additional trigger types not available in the block dialog box. To set the Trigger type parameter to Conditional or Manual, click the Open fault properties hyperlink and set the Trigger type in the Property Inspector.

Dependencies

To enable this parameter, add a fault to the Diode block by clicking the Add fault hyperlink in the Diode fault parameter and set the Trigger type parameter to Additional triggers.

Thermal Port

To enable these parameters, choose one of these options:

Set the Modeling option parameter to Ideal with thermal losses.
Set the Modeling option parameter to Detailed with charge dynamics and select the Show thermal port parameter.

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

Thermal network — Options for thermal network modeling
`Specify junction and case thermal parameters` (default) | `Cauer model` | `Cauer model parameterized with Foster coefficients` | `External`

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 the Thermal network parameter 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
`[0, 10]` `K/W` (default) | vector of nonnegative scalars

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 the Thermal network parameter to Specify junction and case thermal parameters.

Junction and case thermal time constants, [t_J t_C] — Junction and case thermal time constants
`[0, 10]` `s` (default) | vector of nonnegative scalars

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 the Thermal network parameter to Specify junction and case thermal parameters and set the Thermal mass parameterization parameter to By thermal time constants.

Junction and case thermal masses, [M_J M_C] — Junction and case thermal masses
`[0, 1]` `J/K` (default) | vector of nonnegative scalars

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 the Thermal network parameter to Specify junction and case thermal parameters and set the Thermal mass parameterization parameter to By thermal mass.

Junction and case initial temperatures, [T_J T_C] — Junction and case initial temperatures
`[25, 25]` `degC` (default) | vector

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.

Values must be greater than or equal to 0 K.

Dependencies

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

Thermal resistances, [R1 R2 … Rn] — Thermal resistances
`[1, 3, 10]` `K/W` | `[.08, .14, .22, .16]` `K/W` | vector of positive scalars

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

If you set the Thermal network parameter to Cauer model, the default value is [1, 3, 10]. If you set the Thermal network parameter to Cauer model parameterized with Foster coefficients, the default value is [.08, .14, .22, .16].

Dependencies

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

Thermal masses, [M1 M2 … Mn] — Thermal masses
`[.1, .3, 1]` `J/K` | `[.001, .005, .05, .5]` `J/K` | vector of positive scalars

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

If you set the Thermal network parameter to Cauer model, the default value is [.1, .3, 1]. If you set the Thermal network parameter to Cauer model parameterized with Foster coefficients, the default value is [.001, .005, .05, .5].

Dependencies

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

Thermal masses initial temperatures, [T1 T2 … Tn] — Initial temperatures of thermal masses
`[25, 25, 25]` `degC` (default) | vector

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

Values must be greater than or equal to 0 K.

Dependencies

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

Thermal time constants, [t1 t2 … tn] — Thermal time constants
`[1, 3, 10]` `s` | `[7e-05, 7e-04, .01, .08]` `s` | vector of nonnegative scalars

Row vector of n thermal time constant values, where n is the number of Cauer elements in the thermal network. The length of this vector must match the length of Thermal resistances, [R1 R2 … Rn]. With this parameterization, the block computes the thermal masses as M_i = t_i/R_i, where M_i, t_i and R_i are the thermal mass, thermal time, and thermal resistance for the i^th Cauer element (if you set the Thermal network parameter to Cauer model) or Foster element (if you set the Thermal network parameter to Cauer model parameterized with Foster coefficients). If you set the Thermal network parameter to Cauer model parameterized with Foster coefficients, all values must be positive.

Dependencies

Initial node temperatures, [T1 T2 ... Tn] — Initial node temperatures
`[25, 25, 25, 25]` `degC` (default) | vector

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

Values must be greater than or equal to 0 K.

Dependencies

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

Junction thermal mass — Thermal mass of junction
`0.01` `J/K` (default) | positive scalar

Thermal mass of the junction.

Dependencies

To enable this parameter, set the Modeling option parameter to Ideal with thermal losses and set the Thermal network parameter to External.

Utilities

Derived data sheet — Open live script
button

Since R2026b

Click this button to open a MATLAB script that generates a derived data sheet.

For more information about derived data sheets, see Generate Derived Data Sheets.

Basic characteristics — Plot basic I-V characteristics
button

Plot the basic I-V characteristics of the Diode block without building a complete model. Use the plots to explore the impact of your parameter choices on device characteristics.

References

[1] MH. Ahmed and P.J. Spreadbury. Analogue and digital electronics for engineers. 2nd Edition. Cambridge, UK: Cambridge University Press, 1984.

[2] G. Massobrio and P. Antognetti. Semiconductor Device Modeling with SPICE. 2nd Edition. New York: McGraw-Hill, 1993.

[3] Lauritzen, P.O. and C.L. Ma. “A Simple Diode Model with Reverse Recovery.” IEEE^® Transactions on Power Electronics. Vol. 6, No. 2, April 1991, pp. 188–191.

Extended Capabilities

expand all

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

Version History

Introduced in R2008a

expand all

R2026b: Manage model fidelity using a simpler block mask

You now manage the level of fidelity of the Diode block by setting the Modeling option parameter to one of these options: Ideal, Ideal with thermal losses, or Detailed with charge dynamics. These options trade off modeling detail against simulation speed. The key differences are how you model and parameterize losses.

As a result of this change, the block no longer supports some combinations of parameter values. For example, you can no longer combine a low-fidelity piecewise linear I-V curve parameterization with a high-fidelity charge dynamics model.

If you are using an earlier release, see the R2026a documentation for information about the Diode block with the previous parameters and dependencies: https://www.mathworks.com/help/releases/R2026a/sps/ref/diode.html (R2026a).

If you are using R2026b or later but created a model in an earlier release that uses a combination of parameter values that is no longer supported, you can still run the model. The model now uses a legacy implementation of the block. If you want to change any parameters, replace the legacy Diode block with the new Diode block from the Simscape Electrical libraries. The legacy Diode block does not support buttons in the Utilities section or any features added since R2026b. The legacy Diode block will be removed in a future release.

The names of variables in the logged simulation data have also changed. If you have a MATLAB script that uses these variables, update the script to use the new variable names.

Variable Name Before R2026b	Variable Name Since R2026b
`Diode.Diode.i_diode`	`Diode.diode.i`
`Diode.Diode.v_diode`	`Diode.diode.v`
`Diode.thermal_port`	`Diode.thermal.thermalNetwork`
`Diode.accumulatedReverseRecoveryLoss`	`Diode.reverseRecoveryLoss.accumulatedReverseRecoveryLoss`
`Diode.lastReverseRecoveryLoss`	`Diode.reverseRecoveryLoss.lastReverseRecoveryLoss`

R2026b: Generate derived data sheet

To generate a derived data sheet:

Open the MATLAB script by clicking the Open live script button next to the Derived data sheet parameter in the Utilities section of the block dialog box.
In the script that opens, provide values for any additional variables that the data sheet requires.
Click the Generate Data Sheet button in the script.

R2026a: Context menu usability improvements

The basic characteristics plotting option has been moved from the context menu to the block dialog box or Property Inspector of the Diode block. To plot the basic characteristics, open the block dialog box or Property Inspector and set the Modeling option parameter to No thermal port. Then, in the Utilities section, click the Plot button next to the Basic characteristics parameter.

Before R2026a, you plot the basic characteristics by right-clicking the block and selecting Electrical > Basic characteristics from the context menu.

R2026a: Tabulate reverse recovery loss as a function of junction temperature, forward current, and turn-off voltage

You can now tabulate the reverse recovery loss Erec with respect to the junction temperature, forward current, and turn-off voltage by setting the Reverse recovery loss model parameter to Tabulate loss with Tj, If, and Vrec.

Before R2026a, you can only tabulate the reverse recovery loss as a function of the junction temperature and the forward current. The block then uses the value of the Turn-off voltage when measuring recovery loss, Vrec parameter to linearly scale the values of the reverse recovery loss lookup table.

R2024a: Model tabulated reverse I-V characteristics

You can now model the tabulated reverse I-V characteristics for the Diode block.

To model the reverse I-V characteristics, select the Model Zener diode parameter and then specify the new Reverse voltages, Vr(Tj,Ir), Reverse currents, Ir(Tj,Vr), Reverse voltages, Vr and Reverse currents, Ir parameters.

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

R2024a: Junction capacitance voltage variable replaced with Charge of junction capacitance variable

If, in the Capacitance section, you set Parameterization to Use C-V curve data points or Use parameters Cj0, VJ, M & FC, you now specify Initial Targets and Nominal Values for capacitance and charge modeling using the Charge of junction capacitance variable. The Junction capacitance voltage variable is no longer enabled.

If a model you created in an earlier release uses these values for Parameterization and specifies Initial Targets or Nominal Values for the Junction capacitance voltage variable, you must update the model. For more information on how to calculate the charge of junction capacitance, see Junction Capacitance.

R2023b: Show the electronic symbol for a Zener diode in the block icon

The Diode block icon now shows different electronic symbols depending on whether you are modeling a standard diode or a Zener diode. To model a Zener diode, select the Model a Zener diode parameter and specify a finite value for the Reverse breakdown voltage parameter.

Before R2023b, you can model a Zener diode by specifying a finite value for the Reverse breakdown voltage parameter, but the block icon shows the electronic symbol for a standard diode. To enable the Reverse breakdown voltage parameter, set the Diode model parameter to Piecewise linear or Exponential.

If you create a model before R2023b and specify a finite value for the Reverse breakdown voltage parameter, the block now enables the Model a Zener diode parameter by default for backward compatibility.

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 backward compatibility.

R2023b: Model a specific diode using built-in parameterizations

You can now parameterize the Diode block by using built-in parameterizations that represent components from specific suppliers. The parameterizations of these diodes match the manufacturer data sheets. Use these parameterizations to set up this block to replicate the V-I curve for forward voltage from data sheets of specific suppliers. To load a predefined parameterization, double-click the Diode 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.

R2023a: Implement temporal or behavioral triggers for faults using a single parameter

The Enable temporal trigger and Enable behavioral trigger parameters have been removed and are replaced with the Fault trigger parameter. You can set the Fault trigger parameter to Temporal or Behavioral. You can enable only one trigger.

If you created a model in an earlier release and enabled both temporal and behavioral triggers, now only the temporal trigger is enabled. Therefore, the simulation results are different if the behavioral trigger causes the fault in your model.

If you want to trigger a fault at a specific time, set the Fault trigger parameter to Temporal. If you want to determine whether a system fails and, if so, when it fails, set the Fault Trigger parameter to Behavioral.

Diode

Description

Piecewise Linear Diode

Tabulated Diode

Exponential Diode

Zener Diode

Reverse Recovery Losses

Junction Capacitance

Charge Dynamics

Temperature Dependence

Modeling Thermal Effects

Variables

Parameterization

Faults

Generate Derived Data Sheet

Plot Basic I-V Characteristics

Examples

Quantifying IGBT Thermal Losses

Optimize Liquid Cooling System of Inverter

Import Infineon XML Parts into Simscape IGBT and Diode Blocks

TVS Diode Parameterization

Schottky Barrier Diode Characteristics

Parameterize MOSFET and Diode Blocks from Wolfspeed Datasheets

Assumptions and Limitations

Ports

Conserving

+ — Positive terminal electrical

- — Negative terminal electrical

H — Thermal port thermal

Dependencies

Parameters

Modeling option — Level of model fidelity Ideal (default) | Ideal with thermal losses | Detailed with charge dynamics

Part Repository

Part selection — Open Block Parameterization Manager button

Active part — Active part part ID

Dependencies

Status — Restore default part parameters button

Dependencies

Manage — Clear part association button

Dependencies

Main

Forward voltage — Voltage threshold for forward conduction 0.6 V (default) | positive scalar

Dependencies

On resistance — Resistance of the diode in forward conduction 0.3 Ohm (default) | positive scalar

Dependencies

Off conductance — Conductance of the diode in reverse bias 1e-8 1/Ohm (default) | positive scalar

Dependencies

Number of series diodes — Number of diodes connected in series 1 (default) | positive scalar integer

Number of parallel diodes — Number of parallel diodes 1 (default) | positive scalar integer

Show thermal port — Option to expose thermal port Off (default) | On

Dependencies

Diode model — Type of I-V characteristic Piecewise linear | Tabulated I-V curve | Exponential

Dependencies

Table type — Tabulated function Table in If(Tj,Vf) form (default) | Table in Vf(Tj,If) form

Dependencies

Parameterization — Model parameterization Use two I-V curve data points (default) | Use parameters IS and N | Use an I-V data point and IS | Use an I-V data point and N

Dependencies

Currents [I1 I2] — Vector of current values at two points [.0137, .545] A (default) | vector of positive scalars

Dependencies

Voltages [V1 V2] — Vector of voltage values at two points [.6, .7] V (default) | vector of positive scalars

Dependencies

Saturation current, IS — Saturation current 1e-12 A (default) | positive scalar

Dependencies

Emission coefficient, N — Diode emission coefficient 1 (default) | positive scalar

Dependencies

Current I1 — Current value 0.0137 A (default) | positive scalar

Dependencies

Voltage V1 — Voltage value 0.6 V (default) | positive scalar

Dependencies

Ohmic resistance, RS — Series connection resistance 0 Ohm (default) | nonnegative scalar

Dependencies

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, 5.02, 8.35, 13.12] A (default) | matrix of nonnegative scalars

Dependencies

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) | matrix of nonnegative scalars

Dependencies

Junction temperatures, Tj — Vector of junction temperatures [25, 125] degC (default) | vector

Dependencies

Forward voltages, Vf — Vector of forward voltages [.5, .7, .9, 1.3, 1.7, 2.1, 2.5] V (default) | vector of nonnegative scalars

Dependencies

Forward currents, If — Vector of forward currents [.1, .2, .5, 1, 2, 4, 7, 10] A (default) | vector of nonnegative scalars

+ — Positive terminal
electrical

- — Negative terminal
electrical

H — Thermal port
thermal

Modeling option — Level of model fidelity
`Ideal` (default) | `Ideal with thermal losses` | `Detailed with charge dynamics`

Part selection — Open Block Parameterization Manager
button

Active part — Active part
part ID

Status — Restore default part parameters
button

Manage — Clear part association
button

Forward voltage — Voltage threshold for forward conduction
`0.6` `V` (default) | positive scalar

On resistance — Resistance of the diode in forward conduction
`0.3` `Ohm` (default) | positive scalar

Off conductance — Conductance of the diode in reverse bias
`1e-8` `1/Ohm` (default) | positive scalar

Number of series diodes — Number of diodes connected in series
`1` (default) | positive scalar integer

Number of parallel diodes — Number of parallel diodes
`1` (default) | positive scalar integer

Show thermal port — Option to expose thermal port
`Off` (default) | `On`

Diode model — Type of I-V characteristic
`Piecewise linear` | `Tabulated I-V curve` | `Exponential`

Table type — Tabulated function
`Table in If(Tj,Vf) form` (default) | `Table in Vf(Tj,If) form`

Parameterization — Model parameterization
`Use two I-V curve data points` (default) | `Use parameters IS and N` | `Use an I-V data point and IS` | `Use an I-V data point and N`

Currents [I1 I2] — Vector of current values at two points
`[.0137, .545]` `A` (default) | vector of positive scalars

Voltages [V1 V2] — Vector of voltage values at two points
`[.6, .7]` `V` (default) | vector of positive scalars

Saturation current, IS — Saturation current
`1e-12` `A` (default) | positive scalar

Emission coefficient, N — Diode emission coefficient
`1` (default) | positive scalar

Current I1 — Current value
`0.0137` `A` (default) | positive scalar

Voltage V1 — Voltage value
`0.6` `V` (default) | positive scalar

Ohmic resistance, RS — Series connection resistance
`0` `Ohm` (default) | nonnegative scalar

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, 5.02, 8.35, 13.12]` `A` (default) | matrix of nonnegative scalars

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) | matrix of nonnegative scalars

Junction temperatures, Tj — Vector of junction temperatures
`[25, 125]` `degC` (default) | vector

Forward voltages, Vf — Vector of forward voltages
`[.5, .7, .9, 1.3, 1.7, 2.1, 2.5]` `V` (default) | vector of nonnegative scalars

Forward currents, If — Vector of forward currents
`[.1, .2, .5, 1, 2, 4, 7, 10]` `A` (default) | vector of nonnegative scalars

Model Zener diode — Option to model a Zener diode
`Off` (default) | `On`

Zener resistance — Resistance of the diode in reverse breakdown
`0.3` `Ohm` (default) | positive scalar

Reverse breakdown voltage — Reverse breakdown voltage
`30` `V` (default) | positive scalar

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) | matrix of nonnegative scalars

Reverse voltages, Vr — Vector of reverse voltages
`[10, 20, 40, 50, 70, 80, 100]` `V` (default) | vector of nonnegative scalars

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) | matrix of nonnegative scalars

Reverse currents, Ir — Vector of reverse currents
`[1e-06, 2e-06, 5e-06, 1e-05, 2e-05, 5e-05, .0001]` `A` (default) | vector of nonnegative scalars

Reverse recovery loss model — Model for reverse recovery loss
`Fixed loss` (default) | `Tabulate loss with Tj and If` | `Tabulate loss with Tj, If, and Vrec`

Reverse recovery loss — Reverse recovery energy loss per switching cycle
`0` `J` (default) | nonnegative scalar

Scale reverse recovery loss with current and voltage — Option to scale fixed recovery loss with current and voltage
`On` (default) | `Off`

Forward current when measuring recovery loss, Irec — Forward current at which recovery loss is measured
`10` `A` (default) | positive scalar

Turn-off voltage when measuring recovery loss, Vrec — Turn-off voltage at which recovery loss is measured
`10` `V` (default) | positive scalar

Filter time constant for voltage and current values — Time constant for filtering voltage and current
`1e-05` `s` (default) | positive scalar

Reverse recovery loss table, Erec(Tj, If) — 2-D table of recovery loss versus temperature and current
`zeros(2,3)` `J` (default) | matrix of nonnegative scalars

Temperature vector for recovery loss table, Tj — Vector of junction temperatures for recovery loss table
`[25, 125]` `degC` (default) | vector

Forward current vector for reverse recovery loss table, If — Vector of forward currents for recovery loss table
`[0.1, 1, 10]` `A` (default) | vector of nonnegative scalars

Reverse recovery loss table, Erec(Tj, If, Vrec) — 3-D table of recovery loss versus temperature, current, and voltage
`zeros(2,3,2)` `J` (default) | 3-D array of nonnegative scalars

Turn-off voltage vector for reverse recovery loss table, Vrec — Vector of turn-off voltages for 3-D recovery loss table
`[0, 100]` `V` (default) | vector of nonnegative scalars

Parameterization — Modeling junction capacitance
`Fixed or zero junction capacitance` (default) | `Use C-V curve data points` | `Use parameters CJ0, VJ, M & FC`

Junction capacitance — Fixed capacitance across the diode junction
`0` `pF` (default) | nonnegative scalar

Reverse bias voltages [VR1 VR2 VR3] — Vector of reverse bias voltage values
`[.1, 10, 100]` `V` (default) | vector of three nonnegative scalars

Corresponding capacitances [C1 C2 C3] — Vector of capacitance values
`[3.5, 1, .4]` `pF` (default) | vector of nonnegative scalars

Capacitance coefficient, FC — Capacitance coefficient
`0.5` (default) | positive scalar

Zero-bias junction capacitance, CJ0 — Zero-bias junction capacitance
`5` `pF` (default) | positive scalar

Junction potential, VJ — Junction potential
`1` `V` (default) | positive scalar

Grading coefficient, M — Grading coefficient
`0.5` (default) | positive scalar

Peak reverse current, iRM — Peak reverse current
`-7.15` `A` (default) | negative scalar

Initial forward current when measuring iRM — Initial forward current when measuring iRM
`4` `A` (default) | positive scalar

Rate of change of current when measuring iRM — Rate of change of current when measuring iRM
`-750` `A/μs` (default) | negative scalar

Reverse recovery time stretch factor — Reverse recovery time stretch factor
`3` (default) | scalar greater than 1

Reverse recovery time, trr — Reverse recovery time
`115` `ns` (default) | positive scalar

Reverse recovery charge, Qrr — Reverse recovery charge
`150` `nA*s` (default) | positive scalar

Diode turn-off voltage when measuring Erec — Diode turn-off voltage when measuring Erec
`-600` `V` (default) | negative scalar

Stray inductance when measuring Erec — Stray inductance when measuring Erec
`150` `nH` (default) | nonnegative scalar