Active production, UL-recognized triac optoisolator
The MOC3031SR2M from onsemi is an active-production optoisolator with a triac output, rated for 4170Vrms isolation and featuring a built-in zero-crossing circuit. It is UL recognized and ROHS3 compliant.
4170Vrms isolation and 1kV/µs dV/dt for AC mains switching
With 4170Vrms isolation and a minimum static dV/dt of 1kV/µs, this optoisolator provides robust galvanic separation between low-voltage control logic and 250 V off-state AC lines. The high dV/dt immunity prevents false triggering from line transients or inductive load switching. The zero-crossing circuit ensures the triac turns on near the AC voltage zero, minimizing inrush current and conducted EMI — a practical advantage for resistive or lightly inductive loads like heaters, solenoid valves, and lamp ballasts. The LED trigger current (Ift) is 15mA max, and the forward voltage (Vf) is 1.25V typical. The input LED can handle up to 60 mA continuous forward current, giving margin for derating over temperature.
Lifecycle and sourcing: active, ROHS3, surface-mount
Compliance is straightforward: ROHS3 compliant and UL recognized. The Tape & Reel option supports automated pick-and-place for production runs.