What this Triac optoisolator is and where it fits
The FODM3023-NF098 is an onsemi 1-channel Triac output optoisolator in a 4-SMD Gull Wing package, rated for 3750 Vrms isolation and 400 V off-state voltage. It is designed to drive a power Triac or SCR from a low-voltage logic signal, with no zero-crossing circuit so you get random-phase turn-on — useful for phase-angle control or when you need to switch on at any point in the AC cycle. The 5 mA max LED trigger current (Ift) means a 3.3 V or 5 V MCU GPIO can drive it directly through a series resistor, no extra buffer transistor needed. The 70 mA RMS on-state current handles small loads like a solid-state relay pilot or a logic-level power Triac gate. Operating from -40°C to 100°C, it suits outdoor telecom cabinets, industrial motor drives, and factory-floor PLC output modules where the ambient temperature swings wide.
Key ratings that matter for your BOM
The 400 V off-state voltage (Vdrm) covers 120 VAC and 240 VAC line switching with healthy margin — no need for a higher-rated opto unless you are switching 277 VAC or 480 VAC. The 10 V/µs minimum static dV/dt (typical) means the Triac output resists false turn-on from fast mains transients, important in noisy industrial environments. Hold current (Ih) is 300 µA typical, which keeps the output latched once triggered until the load current drops below that threshold at the AC zero-cross. If your load draws less than a few mA, you may need a bleeder resistor across the output to guarantee turn-off. Forward voltage (Vf) is 1.2 V typical at 20 mA If — standard for an infrared LED. The 60 mA absolute max forward current gives headroom for high-temperature or low-CTR drive schemes, but most designs run at 10-20 mA to keep the LED stress low.
Lifecycle and sourcing reality
The package is Tube, and the device carries cUR and UR agency approvals, so it is qualified for North American safety-listed equipment. For BOM planning, this part is not single-sourced — onsemi's FODM3023 family includes several variants (with/without zero-cross, different lead forms). If you need tape-and-reel, check the FODM3023R2 or similar suffix. Submit an RFQ through this page to get a firm lead time and price break for your target volume.