STMicroelectronics: High Junction-Temp TRIACs Enable Smaller Heatsinks, Higher Power Density

February 29, 2008 // Published as a news service by IHS

The TRIACs can be used in universal motor-control applications, such as vacuum cleaners, washing machine drum motors and industrial drives; in hot environments such as cookers, ovens, kitchen hobs and coffee machines and for achieving higher power density on printed circuit boards (PCBs) for heater and high-power motor control.

They can also replace conventional TRIACs in closed environments where the ambient temperature is too high.

ST said the high-junction-temperature TRIACs will enable manufacturers to lower their costs by using smaller heatsinks. In addition, the end product will have more reliable operation in hot environments.

The use of conventional TRIACs, which are specified at 125 degrees Celsius junction temperature, can cause a loss of control of the alternating current (AC) load in environments above this temperature, ST said.

This can lead to hazardous application behavior, due to device parameter derating above 125 degrees Celsius. However, the ST HiTj Snubberless series requires no derating of any parameters up to the maximum junction temperature and achieves a turn-off performance at 150 degrees Celsius.

The TRIACs also deliver high-noise immunity of up to 1,500 volts per microsecond (V/ms). Further cost savings are possible for manufacturers through the elimination of RC snubber circuits and noise filters, according to ST.

The HiTj TRIAC series is produced in TO-220AB, TO-220AB insulated (ceramic) and in D2PAK surface-mount packages. They are all 600 V devices, with current ratings of 8 A, 10 A, 12 A, 16 A and 20 A.

The sensitivity range offered today is 35 mA to 50 mA, and will soon be extended with 10 mA devices, ST said.

The devices are available now in volume production.

Source: STMicroelectronics (ST).