Standard and Snubberless Triacs

ST's triacs designs and manufacturing technology set the industry standards for a wide range of medium-power TRIACs. Standard and Snubberless triacs belong to our STPOWER family.

Our 3-quadrant 1200 V triacs target industrial 3-phase equipment with secured transient immunity.

ST's 600-800 V 3Q and 4Q triacs have 5 to 50 mA gate options on a 0.8 to 40 A span of current ratings. The package range covers surface-mount SMB flat to ceramic-insulated heavy-duty TOP-3 packages (T2650-6PFT4050-6PF).

The diac is both a phase-angle trigger complement for triacs in dimmers and an ignition sequence helper in power supplies of lighting electronics such as compact fluorescent lamps (CFL), tube lamps (TL), and LED lighting solutions.


eDesignSuite is a comprehensive set of easy-to-use design-aid utilities ready to help you streamline the system development process with a wide range of ST products.

Thermal-electrical Simulators for Components

Choose design tool:

AC Switches Simulator

Select ratings and application waveforms
Get junction temperature and blocking voltage graphs
Search and sort suitable devices

Rectifier Diodes Simulator

Select ratings and application waveforms
Estimate power losses
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Supports long mission profiles
Provides power loss and temperature graphs
Helps define heatsink thermal properties

Twister Sim

Help select the right ViPOWER Automotive power device
Supports load-compatibility, wiring harness optimization, fault condition impact and diagnostic analysis
Supports various PCB configurations

TVS Simulator

Specify system ratings and surge waveform
Search and sort suitable devices