TRIAC

Purpose

Ideal TRIAC with optional forward voltage and on-resistance

Library

Electrical / Power Semiconductors

Description

The TRIAC can conduct current in both directions. It is built using two anti-parallel thyristors and controlled by an external gate signal. The TRIAC is modeled by two ideal switches that close if the voltage is positive and a non-zero gate signal is applied. The conducting switch remains closed until the current passes through zero. A TRIAC cannot be switched off via the gate.

Parameters

The following parameters may either be scalars or vectors corresponding to the implicit width of the component:

Forward voltage: Additional dc voltage \(V_\mathrm{f}\) in volts (\(\mathrm{V}\)) when one of the thyristors is conducting. The default is 0.
On-resistance: The resistance \(R_\mathrm{on}\) of the conducting device, in ohms (\(\Omega\)). The default is 0.
Initial conductivity: Initial conduction state of the TRIAC. The TRIAC is initially blocking if the parameter evaluates to zero, otherwise it is conducting.
Thermal description: Switching losses, conduction losses and thermal equivalent circuit of the component. For more information see chapter Thermal Modeling. If no thermal description is given, the losses are calculated based on the voltage drop \(v_\mathrm{on} = V_\mathrm{f} + R_\mathrm{on}\cdot i\).
Thermal interface resistance: The thermal resistance of the interface material between case and heat sink, in (\(\mathrm{K}/\mathrm{W}\)). The default is 0.
Initial temperature: This parameter is used only if the device has an internal thermal impedance and specifies the temperature of the thermal capacitance at the junction at simulation start. The temperatures of the other thermal capacitances are initialized based on a thermal “DC” analysis. If the parameter is left blank, all temperatures are initialized from the external temperature. See also Temperature Initialization.
Switch model (CPU code generation): Select the switch model in the generated code.
Fundamental grid frequency (Hz): Frequency where non-ideal switches in the open state have increased series impedance. The default is 0.

Probe Signals

TRIAC voltage: The voltage measured between the terminals.
TRIAC current: The current flowing through the device to the terminal with the gate.
TRIAC gate signal: The gate input signal of the device.
TRIAC conductivity: Conduction state of the internal switch. The signal outputs \(0\) when the TRIAC is blocking, and \(1\) when it is conducting.
TRIAC junction temperature: Temperature of the first thermal capacitor in the equivalent Cauer network.
TRIAC conduction loss: Continuous thermal conduction losses in watts \((\mathrm{W})\). Only defined if the component is placed on a heat sink.
TRIAC switching loss: Instantaneous thermal switching losses in joules \((\mathrm{J})\). Only defined if the component is placed on a heat sink.