5000 Vrms isolation in a 6-SMD Gull Wing package
The Vishay SFH601-3X017T is a single-channel optocoupler with a phototransistor output that includes a base connection, packaged in a 6-SMD Gull Wing surface-mount package rated for 5000 Vrms isolation. The base pin gives the designer the option to add a base-emitter resistor for improved noise immunity or to tailor the switching speed — a feature not available on standard three-pin phototransistor optos. The 6-SMD Gull Wing footprint is common across this isolation class, so the board layout transfers cleanly if a second-source candidate is needed later.
CTR window: 100% to 200% at 10 mA forward current
The guaranteed current transfer ratio of 100% minimum to 200% maximum at IF = 10 mA means the output transistor is guaranteed to saturate with as little as 10 mA LED drive, and the upper bound prevents the output from saturating too hard and slowing turn-off. This window is tighter than the typical 50-600% range on commodity phototransistor optos, which makes the SFH601-3X017T a better fit for designs where the LED current budget is constrained or where the load resistor value needs a predictable collector current swing.
Switching speed and output ratings
Rise and fall times are 2 µs typical each, with turn-on time of 3 µs and turn-off of 2.3 µs. That places this part in the medium-speed class — fine for 50/60 Hz mains zero-cross detection, relay coil drive, or isolated digital inputs up to a few tens of kHz, but not for high-speed data isolation. The output transistor is rated for 100 V collector-emitter and 50 mA continuous current, with a maximum VCE(sat) of 400 mV at the rated drive. The 1.25 V typical forward voltage on the LED side is standard for an infrared GaAs emitter.
Temperature range and environment
It does not carry an AEC-Q automotive qualification, so it is not a first choice for under-hood or chassis-domain applications, but the wide temperature margin suits most factory-floor and base-station environments where the board sees ambient heat from nearby power stages.