Triac-output optoisolator for AC load switching
The MOC3052M is a 1-channel optoisolator from onsemi with a triac output, designed to drive power triacs or directly switch low-current AC loads. The 4170Vrms isolation barrier separates the low-voltage control side from the mains-referenced load side, meeting UL-recognized safety requirements. It comes in a 6-DIP through-hole package (0.300-inch body width), shipped in Tube form. The 600V off-state voltage rating covers 240VAC line switching with margin; the 1kV/µs minimum static dV/dt reduces false triggering from line transients. The non-zero-crossing output allows phase-angle control, useful for resistive heater modulation or incandescent dimming, but also means the triac can be gated at any point in the AC cycle.
Trigger current and hold current for drive margin
The LED trigger current (Ift) is 10mA maximum, and the typical hold current (Ih) is 220µA. A forward voltage of 1.18V typical at the LED, with a maximum DC forward current of 60mA. These values define the drive budget: a 5V logic output with a 330Ω series resistor delivers about 12mA to the LED, comfortably above the 10mA threshold. The low hold current means the triac stays latched with minimal load current, beneficial for lightly loaded circuits.