TRIAC Helps Designers Improve Thermal Management


Ideal for IoT applications like smart home electronic products

CHICAGO —Littelfuse, Inc. introduced six series of high-temperature sensitive, standard and alternistor TRIAC, designed for use as semiconductor switches in appliances and equipment powered by line AC voltages up to 220VRMS. Available in compact, surface-mount packages, these components are the industry’s first TRIAC with such a high maximum temperature that are available in ratings of 4A, 6A, and 8A. This combination of space-saving packaging, high temperature capabilities and choice of current ratings makes them well-suited for Internet of Things (IoT) applications that require compact design but don’t involve continuous high currents such as smart doorbells, thermostats, ceiling fans/lights, door locks, etc.

The sensitive-type components guarantee low current gate control in Quadrants I and IV to interface directly with digital control circuitry. Standard-type components normally operate in Quadrants I and III and are triggered from the AC line. Alternistor-type components only operate in Quadrants I, II, and III, are triggered from the AC line, and are used in circuits requiring high dv/dt capability. With a maximum junction temperature of 150°C, these components help circuit designers facing thermal management issues due to limited or no heat sinking by providing a larger thermal design margin. Their high surge capabilities simplify handling cold in-rush currents in heater or motor control applications.

Typical applications for TRIAC include:

  • 24VAC control such as smart doorbells, thermostats, sprinkler timers, door locks, etc.

  • 110VAC control such as smart ceiling lights/fans, LED flood lights, etc.

  • AC solenoid/valve control

  • AC heating control and AC motor control

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