Triac output, 400 V off-state, no zero-cross — what that means for the load
The MOC3022SR2M is a 1-channel optoisolator from onsemi with a Triac output, rated for 4170 Vrms isolation between the LED input and the output triac. The 400 V off-state voltage means it can block line voltage up to that peak — suitable for switching 120 VAC or 240 VAC loads through an external triac or SCR. This part has no zero-crossing circuit, so the output triac triggers as soon as the LED current exceeds the 10 mA max trigger threshold. That gives you phase-angle control — you can fire the triac at any point in the AC cycle, which is useful for resistive loads where you want to vary power, or for inductive loads where you need to avoid the zero-cross delay.
Package, reel format, and board integration
The Gull Wing leads give a low-profile surface-mount footprint with good solder-joint inspection access. The supplier device package is 6-SMD.