The STMicroelectronics BTA12-800SWRG is a logic-level sensitive-gate triac rated for 12 A RMS on-state current and 800 V off-state voltage. Its 10 mA maximum gate trigger current lets it switch directly from a microcontroller I/O pin or a low-current driver without a separate transistor stage. The TO-220AB insulated package keeps the mounting tab electrically isolated, simplifying heatsink attachment in metal-enclosure designs. This part is built for AC power control in industrial and appliance applications: motor speed controllers, heater regulators, lighting dimmers, and solid-state relays where a single triac handles the load.
The 12 A RMS on-state current sets the continuous load capability. For a resistive load on a 230 VAC line, this covers about 2.7 kW. The 800 V off-state voltage gives headroom above the peak of a 277 VAC line (392 V peak) plus typical surge margins. The non-repetitive surge rating of 120 A at 50 Hz and 126 A at 60 Hz handles inrush from capacitive loads or motor starts — a key spec for the fuse or breaker coordination study. The 15 mA maximum holding current means the triac stays latched once triggered as long as the load current stays above that floor; designs driving very light loads (below 15 mA) may need a dummy resistor to ensure commutation.
Sensitive gate — direct logic drive
With a maximum gate trigger current of 10 mA and a maximum gate trigger voltage of 1.3 V, the BTA12-800SWRG qualifies as a logic-level sensitive-gate triac. The low trigger current also reduces the drive circuit's component count and PCB area.
The TO-220AB insulated package is a through-hole TO-220-3 with an electrically isolated metal tab.