High-temperature TRIAC helps designers improve thermal management

Littelfuse has introduced six series of high-temperature sensitive, standard and alternistor TRIAC, created for use as semiconductor switches in appliances and equipment powered by line AC voltages up to 220VRMS. Offered in compact, surface-mount packages, these components are claimed to be the industry’s first TRIAC with such a high maximum temperature that are offered in ratings of 4A, 6A, and 8A. This combination of space-saving packaging, high-temperature capabilities and selection of current ratings makes them ideal for IoT applications that need compact design but don’t involve continuous high currents such as thermostats, smart doorbells, ceiling fans/lights, door locks, etc. The sensitive-type components ensure low current gate control in Quadrants I and IV to interface with digital control circuitry. Standard-type components commonly 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 applied in circuits needing high dv/dt capability. With a maximum junction temperature of 150C, these components assist circuit designers facing thermal management issues due to restricted or no heat sinking by giving a larger thermal design margin. Their high surge capabilities ease handling cold in-rush currents in heater or motor control applications. “The combination of the robust clip-attach assembly design and the maximum operating junction temperature ensures the high surge capability needed to withstand short-duration overload conditions,” said Koichiro Yoshimoto, business development manager, Semiconductor Business Unit at Littelfuse. “By offering a choice of current ratings in small, surface-mount packages, these components allow designers to minimise board sizes for low power applications such as LED lighting, solenoid drives and motor drives.