The FODM2701 is a single-channel DC-input transistor-output optocoupler from onsemi, rated for 3750Vrms isolation between input and output. It comes in a 4-SMD gull-wing package — the leads are visible and accessible under a microscope, so rework is straightforward with a soldering iron or hot air. No hidden pads, no underfill to worry about.
CTR range and drive margin
Current transfer ratio is specified at 50% minimum to 300% maximum at a forward current of 5mA. That spread is wider than the FODM217A sibling (which has a 100-600% CTR range at 5mA) — meaning the FODM2701 gives the designer a tighter lower bound, so less LED current is wasted on overdrive margin. The 300mV Vce saturation is lower than the 400mV on the FODM121B, which translates to less voltage drop across the output transistor when the phototransistor is fully on — useful when driving a logic input or a low-voltage relay coil.
Production status and sourcing
It is ROHS3 compliant, so it meets the current EU and global restriction standards without an exemption. We can quote to your BOM quantity against current market pricing — confirm the volume and target lead time with an RFQ.
Package and rework considerations
The 4-SMD gull-wing package has a 2.54mm lead pitch — the same as a standard DIP footprint but surface-mount. The leads are on 1.27mm centres at the body, so a fine-tip iron or a small solder wave works. No hot-air profile needed; just tack one lead, align, and solder the rest. The package is supplied in tube — not tape-and-reel. That means manual placement or tube-fed pick-and-place only; if your line runs only reel-fed feeders, budget for a tube-to-reel transfer or request the tape-and-reel variant (FODM121R2 is one such alternative, though its CTR and Vce differ).