The Vishay VOT8024AB-T3 is a single-channel phototriac optocoupler in a 4-SMD gull-wing package, designed for switching AC loads through an isolated low-voltage control signal. Its output type is a Triac, which means it can conduct in both directions once triggered — suited for AC line switching in industrial controls, solid-state relays, motor starters, and lighting ballasts. The part includes a zero-crossing detection circuit, so the triac turns on only near the AC voltage zero crossing, reducing inrush current and radiated EMI in resistive loads like heaters and incandescent lamps.
Rated at 5300 Vrms isolation, this phototriac provides reinforced insulation between the control side (LED) and the load side (triac), meeting the creepage and clearance requirements for mains-connected equipment in industrial and appliance applications. The 800 V off-state voltage lets the triac block peak AC line voltages well beyond 277 VAC nominal, with margin for 480 VAC systems when derated properly. For a 400 VAC motor drive or a 277 VAC LED streetlight driver, the 800 V rating keeps the triac out of avalanche during line transients.
Trigger and drive characteristics
The LED trigger current (Ift) is 5 mA maximum, which means a standard 5 V or 3.3 V logic output can drive it through a current-limiting resistor — no extra driver transistor needed in most cases. Forward voltage is 1.2 V typical, and the LED can handle up to 50 mA DC continuous, so there is headroom for derating at high ambient temperatures. Once triggered, the triac holds conduction with a typical hold current of 400 µA, which is low enough to stay latched through the zero crossing of a light load like a 10 W LED lamp.
Temperature range and package
Operating from -55 °C to 110 °C, this phototriac covers industrial and outdoor environments — think motor drives in unheated factories, outdoor LED signage, or HVAC actuator controls. The static dV/dt rating of 1 kV/µs minimum ensures the triac does not falsely trigger from fast-rising mains transients, a common failure mode in noisy industrial power lines.
Compliance and lifecycle
It is ROHS3 compliant, and the approval agencies listed include CQC, cUL, UL, and VDE, covering North American and Chinese safety standards. That means no extra qualification paperwork for most industrial and lighting OEMs shipping into those regions.