Triac output with 1 kV/µs dV/dt — no zero-cross
The onsemi MOC3052SM is a 1-channel optoisolator with a Triac output in a 6-SMD Gull Wing package. It provides 4170Vrms of isolation between the LED input and the Triac output, with a 600 V off-state voltage rating. The absence of a zero-crossing circuit means the output triggers immediately when the LED current exceeds the 10 mA maximum Ift threshold, making it suitable for phase-angle control applications where turn-on at any point in the AC cycle is required.
4170Vrms isolation and 600 V blocking
The 4170Vrms isolation rating qualifies the MOC3052SM for reinforced insulation in mains-powered equipment — a solenoid valve driver or solid-state relay input stage on a 230 VAC line stays isolated from the low-voltage logic side. The 600 V off-state voltage blocks the peak of a 400 VAC line, so the Triac holds off until the LED fires it. Static dV/dt is a minimum of 1 kV/µs. This is the rate of rise of off-state voltage the Triac can withstand without false triggering — a commutating snubber may still be needed on inductive loads, but the 1 kV/µs floor covers most contactor and small motor switching without external RC networks. Hold current Ih is 220 µA typical. Once the Triac fires, it latches on until the load current drops below this level near the AC zero-cross. In a 10 mA minimum load circuit the Triac stays latched reliably; below that the output may drop out mid-cycle.
RoHS3 compliant and UL recognized. The UR approval covers the safety isolation rating for North American equipment — a panel builder accepting a UL 508A shop-floor assembly can drop this opto in without a separate component-level investigation.