Galvanic barrier for industrial signal isolation
The FOD817B300 is a single-channel optoisolator from onsemi's FOD817 family, delivering 5000Vrms isolation between a DC-input LED and a phototransistor output in a 4-DIP through-hole package. With a current transfer ratio (CTR) range of 130% to 260% at 5mA forward current, this B-bin part provides a predictable gain window for sizing the primary-side LED drive and the secondary-side pull-up resistor. The 70V output breakdown and 50mA continuous output current handle typical logic-level and low-power load switching in PLC digital inputs, AC motor drive feedback, and SMPS feedback loops.
ROHS3 compliant, with no exemption conflicts for EU-market equipment. The 4-DIP (0.300", 7.62mm) through-hole package is a standard footprint, readily hand-solderable or wave-solderable.
Sourcing and package availability
The 4-DIP body is compatible with existing pick-and-place feeders that handle tube-fed DIPs; for high-volume reels, check the FOD817 series for tape-and-reel variants. The closest functional alternative within the same family is the FOD817B (same CTR bin, same package), but the FOD817B300 suffix indicates a specific tube quantity or factory code — verify the BOM line's exact ordering code before substituting.