The FOD817SD delivers 5000 Vrms galvanic isolation between the DC input and the transistor output — enough to separate a 24 V PLC digital input from a 5 V logic rail or to break ground loops in a motor drive feedback path.
Temperature range and switching speed
Rated for -55°C to 110°C operating ambient, the FOD817SD suits both cold-start industrial enclosures and hot engine-bay electronics. The typical rise and fall times are 4 µs and 3 µs respectively — fast enough for 100 kHz-level feedback loops or low-speed serial isolation, but not intended for high-speed data links. Output transistor saturation voltage is 200 mV max, keeping the logic-low level clean when the phototransistor is fully on. Maximum output voltage is 70 V, and continuous output current per channel is 50 mA — adequate for driving a downstream optocoupler or a small relay coil.
The gull wing leads provide visual solder-joint inspection access and moderate standoff for cleaning under the body.
Active lifecycle — sourcing posture
The base product number is FOD817, and this variant (FOD817SD) is the surface-mount gull-wing version of the standard DIP-4 FOD817 series.