Active production – 5000Vrms isolation in a 4-SMD Gull Wing
The FOD817D3SD is an active-production onsemi optoisolator with a transistor output and a DC input. It packs 5000Vrms of isolation into a 4-SMD Gull Wing package — the kind of part you can swap on site with a soldering iron and a steady hand, no hot-air station needed. The 300% to 600% current transfer ratio at 5 mA forward current gives you headroom for LED degradation over the life of the equipment. If the primary-side LED dims, the output transistor still saturates cleanly.
Temperature range and output drive – field-fit realities
The output transistor can sink 50 mA continuously with a Vce saturation of 200 mV max — enough to drive a PLC input or a relay coil directly.
Sourcing and compliance – ROHS3, no obsolescence watch
Marked as Active with ROHS3 compliance. The base product number is FOD817, so the D3SD suffix selects the CTR bin and Gull Wing package variant.