12 A RMS, 800 V — AC load switching in a TO-220F isolated tab
The NXP BTA312X-800B,127 is a standard triac rated for 12 A RMS continuous on-state current and 800 V off-state blocking voltage — sized for switching resistive or inductive AC loads up to roughly 2.5 kW on a 230 V line, or 5 kW on 400 V three-phase legs when derated for the duty cycle. The TO-220F full-pack (isolated tab) package means the metal tab is electrically isolated from the die — no separate insulating washer or pad is needed when bolting to a heatsink, which simplifies assembly and reduces BOM count in panel-mount or PCB-mount designs.
Gate drive margin and surge capability
Maximum gate trigger current is 50 mA and maximum gate trigger voltage is 1.5 V — the triac fires reliably from a standard 5 V logic output or a 24 V PLC digital output with a series resistor, without needing a separate driver IC. Holding current is 60 mA max — once triggered, the triac stays latched above this load current, which is well below the typical running current of a motor or heater load, so it will not drop out mid-cycle on a lightly loaded phase. Non-repetitive surge current is 95 A at 50 Hz and 105 A at 60 Hz — this covers the inrush from a motor start or capacitor bank charge without exceeding the device's peak current rating, as long as the surge duration stays within the half-cycle window.