What this optoisolator does on your board
The FOD2741BTV is a single-channel transistor-output optoisolator from onsemi, rated for 5000Vrms isolation between input and output. That isolation rating puts it in the class for reinforced insulation in industrial PSU feedback loops, motor-drive gate drive interfaces, and PLC digital I/O where the field side must stay galvanically separated from the controller side. The input is DC-driven with a forward voltage max of 1.5V; the output transistor can sink up to 50 mA continuous with a Vce saturation ceiling of 400 mV. The current transfer ratio is guaranteed between 100% and 200% at a 10 mA LED current — tight enough to design a logic-level interface without overdriving the LED or guessing the output current.
Temperature grade and package — where it fits
The 8-DIP (0.400", 10.16 mm) through-hole package with 8-MDIP supplier device code is a standard footprint — no fine-pitch soldering, easy for rework or manual assembly. Mounting is through hole, supplied in a tube. The 10.16 mm body width is the wider DIP variant, so confirm the socket or PCB hole pattern matches the 0.400-inch row spacing before committing the layout.