800 V off-state and zero-crossing for 240 VAC mains switching
The TLP3083(TP1,F is a Toshiba triac-output optoisolator rated for 800 V off-state voltage — that is a full 1.7× margin above a 240 VAC peak of 339 V, so it handles mains transients without avalanche. The built-in zero-crossing circuit triggers the triac only near the AC zero crossing, which cuts inrush current and EMI from resistive and lightly inductive loads like solenoids and contactors. The 5000 Vrms isolation rating satisfies reinforced insulation requirements for line-voltage interfaces in industrial controls, HVAC, and appliance power stages.
Parametric deep-dive: dV/dt immunity and drive current
Static dV/dt is rated 2 kV/µs typical — the triac output will not false-fire on fast voltage edges from relay coil kickback or motor commutator noise. On-state RMS current is 100 mA max — that drives small triacs or solid-state relays directly, but for loads above 100 mA you need an external power triac. The 1.15 V typical forward voltage and 600 µA typical hold current are standard for the family.