The STMicroelectronics T830-800W is an 800 V, 8 A RMS Snubberless™ alternistor triac in the ISOWATT220AB-3 through-hole package. The Snubberless construction means the device is designed for inductive loads without requiring an external snubber network, simplifying the BOM and board layout in motor drives, lighting ballasts, and industrial AC switching applications. The 800 V off-state voltage provides margin for 240 VAC mains with surge transients, while the 8 A RMS on-state current handles moderate loads such as fans, pumps, and solenoid valves.
Trigger and hold characteristics for reliable commutation
Maximum gate trigger current is 30 mA and maximum gate trigger voltage is 1.3 V, which is compatible with standard logic-level or optocoupler drive circuits. The 50 mA maximum hold current ensures the triac stays latched through the zero-crossing of an inductive load, reducing the risk of premature turn-off. The non-repetitive surge current rating of 100 A at 60 Hz (105 A at 50 Hz) gives headroom for inrush events during motor start or lamp cold-filament turn-on.
Obsolete — sourcing and replacement reality
The Snubberless alternistor topology is shared across the T8xx series, but pin compatibility and trigger thresholds vary by suffix.
Temperature range and package — design constraints
The ISOWATT220AB-3 through-hole package provides isolation between the tab and the heatsink, simplifying thermal management in metal-enclosure designs. The single-triac configuration and through-hole mounting suit point-of-load AC switching where board space is not the primary constraint.