The ST BTA12-700CWRG is a Snubberless™ Alternistor triac rated for 700 V off-state and 12 A RMS on-state current in a TO-220 through-hole package. It switches AC loads without the RC snubber network that older triac designs need — the Alternistor construction handles inductive turn-off commutation internally, which simplifies the BOM and cuts the parts count on the power board. The 35 mA gate trigger current and 1.3 V gate trigger voltage are standard for this current class — any microcontroller GPIO driving an opto-triac or a discrete driver will hit the gate without extra gain stages.
Surge current and hold current — the real-world margins
Non-repetitive surge current is 120 A at 50 Hz and 126 A at 60 Hz — this is the number the incoming fuse or circuit breaker must coordinate with so the triac survives the cold-start inrush of a motor or a bank of incandescent lamps. Maximum holding current is 35 mA. If the load current dips below this near the zero-crossing, the triac drops out of conduction — a consideration for low-power loads or PWM dimming where the gate pulse must be maintained through the entire half-cycle.