AC-line blocking and transient immunity
The FOD4216S is a single-channel Triac-output optoisolator rated for 600 V off-state voltage — sufficient to block the peak of a 240 VAC or 480 VAC line without self-triggering. The 10 kV/µs minimum static dV/dt keeps the output from false-firing on fast voltage edges from motor drives, contactor coils, or switched inductive loads. With no zero-crossing circuit, the triac fires immediately when the LED current exceeds the 1.3 mA max trigger threshold. This suits phase-angle control, resistive heater modulation, and any application where turn-on timing relative to the AC waveform matters.
Parametric deep-dive: drive current and hold current
The LED forward voltage is 1.28 V typical at 30 mA max DC forward current. The 500 µA hold current means the triac latches once triggered and stays on until the load current drops below that level — typical for AC loads where the current crosses zero naturally each half-cycle. Turn-on time is 60 µs, fast enough for most line-frequency switching but not for high-frequency PWM. The 5000 Vrms isolation with cUL, FIMKO, and UL approvals supports reinforced insulation requirements in industrial and appliance power supplies.
in a 6-SMD Gull Wing package for surface-mount assembly.