Isolation barrier and working voltage fit
The FOD817BS delivers 5000Vrms isolation between input and output — a reinforced-grade barrier suitable for mains-referenced circuits, motor-drive feedback, or any application where the secondary side must be galvanically isolated from the primary control logic. With a DC input and phototransistor output, this is the standard optocoupler topology for isolating logic-level signals up to 70V and 50mA on the output side.
CTR range and drive margin
Current transfer ratio spans 130% to 260% at a forward current of 5mA — the minimum CTR of 130% ensures the output transistor saturates with enough margin to drive a standard CMOS or TTL input even when the LED is driven at its lower end. The 200mV Vce saturation at 50mA output means the collector-emitter voltage drop stays low when sinking current, keeping the output logic-low level well within the threshold of a 3.3V or 5V receiver.
Temperature grade and switching speed
Rated for -55°C to 110°C operating ambient — the industrial temperature grade covers outdoor telecom cabinets, factory-floor PLC racks, and under-hood automotive modules (though not formally AEC-Q qualified per the record). Typical rise and fall times of 4µs and 3µs respectively give a practical switching ceiling around 50-100 kHz for isolated data or PWM signals — fast enough for most sensor feedback and gate-drive isolation, though not for high-speed digital buses.
Housed in a 4-SMD Gull Wing package (supplier device package 4-SMD), the FOD817BS is a surface-mount device that reflows on standard pick-and-place lines. The Gull Wing leads provide good solder joint inspection access and mechanical compliance on FR4. Supplied in Tube packaging — the tube format is typical for low-volume assembly or prototyping; for high-volume reel packaging, check the FOD817 series ordering options.