8 A RMS, 800 V off-state — Snubberless™ alternistor for inductive loads
The T835T-8FP is an 8 A RMS (It(RMS)) triac from STMicroelectronics' Snubberless™ series, rated for 800 V off-state voltage. It is an alternistor type — a snubberless design that commutates inductive loads without the external RC snubber normally required for standard triacs, simplifying the BOM and saving board space. Packaged in a TO-220-3 Full Pack (TO-220FPAB), the fully isolated tab means the heatsink does not need an insulating pad — a time-saver on the assembly line and a reliability win in high-vibration environments. The device handles non-repetitive surge currents of 60 A at 50 Hz and 63 A at 60 Hz (Itsm), giving it the headroom to survive motor inrush or capacitor charging events without failing short.
Maximum gate trigger current (Igt) is 35 mA, with a maximum gate trigger voltage (Vgt) of 1.3 V. This is a standard logic-level drive — a microcontroller GPIO through a transistor or optocoupler can fire it, but the 35 mA ceiling means the driver must source at least that much at the trigger threshold. The 40 mA maximum hold current (Ih) ensures the triac stays latched once triggered, even with a lightly inductive load that might otherwise drop below the holding threshold.