Isolation barrier and output drive — what the 5000Vrms and 50 mA mean on the board
The FOD8173S provides 5000Vrms isolation between the DC input LED and the phototransistor output — a reinforced insulation class that suits mains-referenced control circuits, motor-drive feedback, and medical patient-interface barriers where the safety agency demands a 5 kV rating. Output is a single NPN phototransistor rated to 70 V and 50 mA continuous — enough to drive a PLC digital input, a relay coil through a transistor buffer, or a logic-level gate without an extra gain stage.
Temperature range and switching speed — fit for industrial control loops
Surface-mount assembly and package availability
The 4-SMD Gull Wing package (supplier device package 4-SMD) is a surface-mount footprint that reflows on a standard lead-free profile — no through-hole wave-solder step, which saves a process pass on a mixed-technology board. Supplied in Tube — the tube quantity is the standard for this package; for tape-and-reel volume, the sibling FOD817ASD is the reeled variant if your pick-and-place line is set up for reel feed.
ROHS3 compliant. No PCN or LTB risk for the current BOM cycle.