Designed for high immunity against glitches on mains and high load supplies, the Thyristors, also known as silicon-controlled rectifiers (SCR), triacs and logic-level gate ACS circuits are switches working on 120, 240 and 480 V AC power lines for appliances, tools, converters and drive systems. Thyristors (SCR) and AC Switches belong to our STPOWER family.
The most energy efficient, simplest gate drive, Thyristors, are also the toughest 200 to 1400 V bidirectional switch for controlling alternating current mains power.
With a current range from 0.2 to 80 A, Thyristors are used in home and office appliances, as well as industrial automation. More concretely, AC switch circuits are included in compressor drives, water heater, power tools, static relays, roller shutters, motorbike regulators and more recently, circuit breakers and electrical vehicle chargers.
Smart-building connected objects powered by AC mains is the latest innovation where Thyristors are contributing to climate and energy controls.
To meet the wide variety of assembly automation requirements, ST's portfolio offers a full range of surface-mount SMD packages from the tiniest 0.8 A SMB Flat ACS to the power-carrier 80 A D3PAK SCRs. Our through-hole packages include the thermally excellent 2500 V ceramic-insulated TO-220 and the new full resin-molded TO-220 package.
Explore our large choice of packages for our thyristors (SCR), Triacs and ACS switches.
Quickly find the thyristor or AC switch that best fits your design by simply entering the main I/O and gate parameters in our AC Switch Simulator.
Triacs
Today’s triacs are perfected with low gate current drive, high immunity and commutation at temperature (see our T series and H series).
AC Switches
Our ACS™ AC switches ensure the interface between a gate and an MCU with an integrated over-voltage protection (OVP) function.
SCRs
Silicon-controlled rectifiers (SCR) are the most immune switch to voltage spikes and their load commutation capability is very high.
ASD
ASDs (Application-Specific Discretes) are a collection of gas and fuel ignitors integrating SCR building blocks.
Featured Videos
ST’s 8H Triacs have been designed for Industrial, Building, Residential, Appliances. Based on the new ST’s technology, the 8H Triacs are able to work at 800V & 150°C without compromise. It makes 8H Triacs the right choice to run in very hot confined electronic environment and improve the reliability of your system. Thanks to 8H Triacs robust dynamic turn-off commutation and high noise immunity at high temperature you can reduce your system size while increasing functional safety.
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