The STMicroelectronics T1620T-8I is a Snubberless™ Alternistor triac in a TO-220-3 through-hole package. It switches AC loads up to 16 A RMS with an 800 V off-state voltage rating, and it is designed to commutate inductive loads — motors, solenoids, transformers — without the external RC snubber that standard triacs need.
16 A RMS and 800 V — what the ratings mean on the panel
The 16 A RMS current rating is the continuous load this triac can handle when properly heatsunk. For a resistive heater drawing 12 A continuous, you have headroom. For a motor with a 15 A locked-rotor inrush, the 120 A / 126 A non-repetitive surge rating covers the start-up event. The 800 V off-state voltage gives margin on a 480 VAC line (peak ~679 V) and handles mains transients without avalanche failure. Gate trigger is specified at 20 mA max with a 1.3 V max gate trigger voltage — standard logic-level drive from a microcontroller or optocoupler will fire it directly.
Active production — no LTB worry
The Snubberless™ series remains a current product line from ST.
