Triac output with zero-crossing — AC load switching
The onsemi MOC3041SVM is a single-channel optoisolator with a Triac output and an integrated zero-crossing circuit, delivering 4170Vrms of galvanic isolation between the LED input and the output triac. Rated for 400 V off-state voltage and a minimum static dV/dt of 1 kV/µs, this part is built to switch resistive or inductive AC loads without false triggering on line transients.
Zero-crossing circuit — why it matters for the BOM
The zero-crossing circuit turns on the Triac only when the AC mains voltage crosses near zero, which reduces inrush current into the load and lowers conducted EMI at switch-on. This makes the MOC3041SVM a natural fit for driving resistive loads like heaters or incandescent lamps where soft turn-on extends relay and triac life. The LED trigger current (Ift) is 15 mA max, and the typical hold current (Ih) is 400 µA — the input side needs a 15 mA forward current to latch the output, and the triac stays on until the load current drops below 400 µA.
Package and board-fit — 6-SMD Gull Wing
Housed in a 6-SMD Gull Wing package, the MOC3041SVM is a surface-mount part supplied in Tube — the Gull Wing leads provide a visible solder joint for inspection and rework.
Approvals include IEC/EN/DIN and UL — the UL listing covers the 4170Vrms isolation rating, which is the figure a safety engineer uses to demonstrate reinforced insulation in a power supply or motor drive interface.