The SFH620A-2X007T: This isolation rating is the key parameter for applications where safety isolation or ground-loop breaking is required — it meets reinforced insulation requirements per IEC 60950-1 for mains-connected equipment.
AC/DC input and CTR range for drive margin
The input stage accepts both AC and DC drive signals, which means the same part can be used whether the control signal comes from a DC logic output or an AC line — no external bridge rectifier needed. The forward voltage is 1.25 V typical at 10 mA, and the maximum continuous forward current is 60 mA. The current transfer ratio (CTR) is specified as 63% minimum and 200% maximum at 10 mA forward current. This 3:1 spread means the designer must size the pull-up resistor for the worst-case minimum CTR to guarantee the output saturates — at 63% CTR and 10 mA input, the output can sink at least 6.3 mA into the load. The 200% ceiling ensures the output does not saturate too hard, which matters for switching speed. Output-side ratings: the phototransistor can handle up to 70 V across the collector-emitter and 50 mA continuous current per channel.
Switching speed and temperature range
The turn-on time is 3 µs typical and turn-off time is 2.3 µs typical, with rise and fall times of 2 µs each. This limits the practical data rate to roughly 100 kbps — adequate for status feedback, relay drivers, and PLC input isolation, but not for high-speed serial links.