5 kV isolation for line-voltage triac switching
The FOD410TV is an onsemi optoisolator with a triac output rated for 5000 Vrms isolation — enough to separate a 5 V or 24 V logic-side controller from a 240 VAC load circuit without galvanic creepage worries in a 6-DIP package. The 600 V off-state voltage rating means it can handle the peak of a 240 VAC line (339 V peak) with margin for transients. A built-in zero-crossing circuit triggers the triac only near the AC voltage zero, which limits inrush current into resistive loads like heaters or incandescent lamps and reduces conducted EMI. For phase-angle or PWM dimming applications, the non-zero-cross sibling FOD4208V is the better fit.
Static dV/dt and hold-current margins for inductive loads
Minimum static dV/dt is 10 kV/µs — this is the rate of voltage rise the triac can withstand across its terminals without false turn-on. In a motor-drive or solenoid environment where contactors or relays generate fast line transients, that rating keeps the output off when it should be off. Hold current (Ih) is 500 µA typical. Once the triac is triggered, it latches on until the load current drops below that threshold near the AC zero crossing. For low-current loads below ~10 mA RMS, confirm the load current exceeds Ih over the full temperature range; at elevated temperature Ih drops, but the datasheet min/max boundaries are the safe design target.
Active production, through-hole package, and ordering
Approvals include CSA, UL, and VDE, covering North American and European safety certification for reinforced insulation. Operating temperature spans -55°C to 100°C, adequate for industrial enclosures but not extended for under-hood automotive — no AEC-Q rating is listed.