1.2 kV off-state, 40 A RMS — snubberless switching for industrial loads
The STMicroelectronics TPDV1240RG is an Alternistor - Snubberless triac rated for 1.2 kV off-state voltage and 40 A RMS on-state current, housed in a TOP-3 through-hole package. The snubberless construction means it can switch inductive loads — motors, solenoids, transformers — without the external RC snubber network that standard triacs require, saving two components and the layout space for them.
370 A surge — inrush margin for motor and capacitor loads
Non-repetitive surge current is rated 350 A at 50 Hz and 370 A at 60 Hz. That surge rating covers the inrush from a motor start or a discharged capacitor bank — the triac will survive the first half-cycle spike without failing short. The 50 mA maximum holding current (Ih) ensures the device stays latched once triggered, even with a lightly loaded phase.
Gate drive: 200 mA trigger, 1.5 V gate threshold
Gate trigger current (Igt) is 200 mA maximum, and gate trigger voltage (Vgt) is 1.5 V maximum. A standard optocoupler or pulse transformer with a 200 mA peak output will drive this gate directly — no intermediate driver stage. The single triac configuration means one gate drive circuit per device, keeping the BOM simple.