Triac-output optocoupler for AC load switching
The FODM3052V-NF098 is a single-channel triac-output optoisolator from onsemi. It provides 3750Vrms galvanic isolation and a 600 V off-state voltage rating. No zero-crossing circuit is built in, so the triac fires immediately when the LED current exceeds the 10 mA max trigger threshold. This makes the part suitable for phase-angle dimming or random-turn-on applications where zero-cross switching would delay the response.
Parametric limits that shape the BOM
The minimum static dV/dt of 1 kV/µs prevents false triggering on fast-rising line voltage edges — a common failure mode when switching inductive loads like motors or transformers. If your load generates transients steeper than that, add a snubber across the triac. On-state current is rated 70 mA RMS maximum, so this optocoupler drives a gate-drive triac or a small load directly, not a high-current contactor. The typical hold current is 450 µA, meaning the triac drops out when the load current falls below that level — relevant for low-power loads that might not sustain conduction. Forward voltage is 1.2 V typical at 60 mA max DC forward current. The LED trigger current is 10 mA max.