Mains-isolated triac drive with 5 kV barrier
The FOD4116SD is a single-channel optoisolator with a triac output, designed to drive a power triac or directly switch low-current AC loads from a logic-level control side. Its 5000 Vrms isolation rating and 600 V off-state voltage suit it for mains-referenced applications where safety isolation is mandatory. The zero-crossing circuit ensures the output triac turns on only near the AC line zero-crossing, minimising inrush current and conducted EMI — a benefit for resistive heater, lamp, and motor contactor loads.
Transient immunity and trigger thresholds
A minimum static dV/dt of 10 kV/µs prevents false turn-on from fast voltage spikes on the output side, critical in industrial environments with inductive load switching or nearby contactors. The LED trigger current (Ift) is 1.3 mA max, allowing direct drive from a 3.3 V or 5 V logic output with a series resistor. Forward voltage is 1.25 V typical, and maximum continuous LED current is 30 mA. Turn-on time is 60 µs, fast enough for most AC switching cycles but not intended for high-frequency PWM. The hold current (Ih) is 500 µA, meaning the output triac will commutate off when the load current drops below this level near the AC zero-cross.
Active lifecycle and compliance status
This supports ongoing BOM stability for production runs requiring a UL- and CSA-approved optotriac. The part is in a 6-SMD gull-wing package, surface-mount for automated assembly.