Triac output optoisolator for line-voltage load switching
The Vishay VO2223 is a 1-channel optoisolator with a power Triac output, packaged in a 7-lead 8-DIP (0.300", 7.62mm) through-hole package supplied in Tube. It provides 5300Vrms isolation between the LED input and the Triac output stage, making it suitable for driving resistive or inductive loads directly from a microcontroller without a separate relay or contactor. The off-state voltage rating of 600 V allows the Triac to switch loads on 120 VAC or 240 VAC lines with margin for mains transients. The 900 mA RMS on-state current handles small solenoid valves, indicator lamps, or solid-state relay primary coils without an external driver.
dV/dt immunity and zero-crossing design choice
A minimum static dV/dt of 210 V/µs (Typ) means the Triac will not falsely trigger from fast-rising mains voltage edges — critical when switching inductive loads like contactor coils or small motors where the line voltage can slew sharply at turn-off. This is a typical value; the datasheet min/max should be checked for the specific operating condition. The VO2223 has no zero-crossing circuit. That means the Triac can be triggered at any point in the AC waveform, not just near the zero crossing. This gives the designer control over phase-angle firing for dimming or soft-start, but also means the load sees the full instantaneous voltage at turn-on — a consideration for inrush-sensitive loads. The LED trigger current (Ift) is 10 mA max, and the forward voltage (Vf) is 1.3 V max.
The part carries cUR and UR approval marks, certifying it for use in UL-recognized equipment in North America.