Ideal Semiconductor Switch

R2026b

Ideal Semiconductor Switch

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Ideal Semiconductor Switch block

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Libraries:
Simscape / Electrical / Semiconductors & Converters

Description

The Ideal Semiconductor Switch block models an ideal semiconductor switching device.

The figure shows a typical i-v characteristic for an ideal semiconductor switch.

If the gate-cathode voltage exceeds the specified threshold voltage, the ideal semiconductor switch is in the on state. Otherwise the device is in the off state.

In the on state, the anode-cathode path behaves like a linear resistor with on-resistance R_on.

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

Using the Integral Diode parameters, you can include an integral cathode-anode diode. An integral diode protects the semiconductor device by providing a conduction path for reverse current. An inductive load can produce a high reverse-voltage spike when the semiconductor device suddenly switches off the voltage supply to the load.

Examples

SEPIC Voltage Control

Control the output voltage of a single-ended primary-inductor converter (SEPIC). The SEPIC is a form of DC-DC converter designed to deliver a regulated positive output voltage, regardless of whether the input voltage is higher, equal to, or lower than the intended output voltage. The Control subsystem adjusts the duty cycle of the semiconductor switch to regulate the output of the SEPIC. To adjust the duty cycle, the Control subsystem uses a PI-based control algorithm. The input voltage is constant throughout the simulation. A resistor provides the load for the system. The total simulation time is 0.1 seconds.

• Since R2024a
• Open Model

Mars Helicopter System-Level Design

Use Simscape™ Electrical™ to model a helicopter with coaxial rotors suitable to fly on Mars. This helicopter takes inspiration from Ingenuity, the robotic helicopter developed by NASA, which accomplished the first powered flight on another planet.

• Open Model

Assumptions and Limitations

The Ideal Semiconductor Switch 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

This figure shows the block port names.

Input

G — Gate terminal

physical signal

Physical signal port associated with the gate terminal.

Dependencies

To enable this port, set Gate-control port to PS control port.

Conserving

G — Gate terminal

electrical

Electrical conserving port associated with the gate terminal.

Dependencies

To enable this port, set Gate-control port to Electrical control port.

A — Anode terminal

electrical

Electrical conserving port associated with the anode terminal.

K — Cathode terminal

electrical

Electrical conserving port associated with the cathode terminal.

Parameters

Main

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

PS (default) | Electrical

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

On-state resistance — On-state resistance

0.001 Ohm (default)

Anode-cathode resistance when the device is on.

Off-state conductance — Off-state conductance

1e-6 1/Ohm (default)

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

Threshold voltage, Vth — Threshold voltage

0.5 V (default)

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

Integral Diode

Integral protection diode — Protection diode

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

Model that the Ideal Semiconductor Switch block uses for the integral protection diode. Choose one of these options:

• External diode — The Ideal Semiconductor Switch does not model an integral protection diode. Use an external Diode block.

• Diode with no dynamics — The Ideal Semiconductor Switch block models the integral protection diode using the same equations as the Diode block with no dynamics.

The Diode with charge dynamics option is not recommended and will be removed in a future release. The Ideal Semiconductor Switch block uses a simple model for the switching device that simulates fast. Combining this low-fidelity model with a high-fidelity model for the integral diode requires smaller simulation time steps, reducing the benefits of the low-fidelity model. Combining these models might also cause numerical issues during simulation. If you need a low-fidelity model, set this parameter to Diode with no dynamics. This option does not use a physics-based charge model but you can still include the thermal effect of reverse recovery by specifying a fixed or tabulated loss. The block represents the losses that the charge creates during reverse recovery as an instantaneous loss and steps up the junction temperature with a value equal to the reverse recovery loss divided by the total thermal mass at the junction. If you need a high-fidelity model, use a different block to model the switching device. For more information about choosing the level of fidelity you need to achieve your simulation goals, see Choose Blocks to Model Semiconductor Devices.

For more information on these parameters, see Diode.

Extended Capabilities

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

Version History

Introduced in R2013b

R2026b: Diode with charge dynamics is not recommended

The Diode with charge dynamics option of the Integral protection diode parameter is not recommended and will be removed in a future release.

The Ideal Semiconductor Switch block uses a simple model for the switching device that simulates fast. Combining this low-fidelity model with a high-fidelity model for the integral diode requires smaller simulation time steps, reducing the benefits of the low-fidelity model. Combining these models might also cause numerical issues during simulation.

If you need a low-fidelity model, set the Integral protection diode parameter to Diode with no dynamics. This option does not use a physics-based charge model but you can still include the thermal effect of reverse recovery by specifying a fixed or tabulated loss. The block represents the losses that the charge creates during reverse recovery as an instantaneous loss and steps up the junction temperature with a value equal to the reverse recovery loss divided by the total thermal mass at the junction.

If you need a high-fidelity model, use a different block to model the switching device.

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