Zero-crossing triac driver for AC load switching
The MOC3061M is a 1-channel optoisolator with a Triac output and an integrated zero-crossing circuit. The zero-crossing gate ensures the output triac turns on only when the AC line voltage is near zero, which dramatically reduces the inrush current spike into motors, solenoids, transformers, and incandescent lamps — a key advantage over random-phase optotriacs that can fire at any point on the waveform. The minimum static dV/dt of 600 V/µs means the output triac will not falsely trigger from fast voltage transients on the AC line or from adjacent switching edges.
Isolation and drive requirements for the BOM
Rated at 4170 Vrms isolation, the MOC3061M can directly drive a 600 V off-state triac from a low-voltage logic side — no isolated DC-DC converter needed on the high side. The maximum continuous LED forward current is 60 mA. The hold current (Ih) is 500 µA typical — the triac will drop out of conduction if the load current falls below this threshold near the AC zero crossing, which is normal for zero-crossing parts and prevents partial conduction on the next half-cycle.
The 6-DIP through-hole package is supplied in Tube. For volume requirements or if the MOC3061M is on allocation, the closest functional sibling within the same MOC306x family is the MOC3062M, which shares the same 600 V/µs dV/dt, zero-crossing, and 4170 Vrms isolation ratings. The MOC3061VM and MOC3061TVM add IEC/EN/DIN safety approvals alongside UL — a consideration if the end equipment must carry a CE mark for industrial or appliance use.