The onsemi CNY17F2300W is a single-channel transistor-output optocoupler in a through-hole 6-DIP package (0.400", 10.16 mm pitch). It provides 5300 Vrms galvanic isolation between a DC input LED and a phototransistor output — a common choice for breaking ground loops in industrial PLC digital inputs, motor drive feedback, and isolated serial interfaces. The current transfer ratio (CTR) is specified at 63% minimum and 125% maximum when the LED is driven at 10 mA — this spread tells you the output transistor's collector current will be between 6.3 mA and 12.5 mA for that input condition. A tight CTR bin like this (the '230' suffix) makes it easier to design the pull-up resistor and guarantee the logic threshold across temperature and unit-to-unit variation. Output side: the phototransistor can sink up to 50 mA continuous and block 70 V across the collector-emitter. Saturation voltage is 300 mV max at the rated current — low enough to drive a 5 V logic input directly without a second transistor. Switching is modest: 1 µs rise, 2 µs fall typical, with turn-on/turn-off times of 2 µs and 3 µs respectively. That suits 10-100 kHz isolated data or PWM signals, not high-speed digital buses.
No pin-compatible direct replacement from onsemi has been announced, so a board redesign may be needed if the supply window closes.
Temperature grade and environment
Rated for -55°C to +100°C operating ambient — the full industrial temperature range with margin into military cold. The 6-DIP through-hole package handles wave soldering and is field-replaceable without hot air. The 5300 Vrms isolation rating (1-minute test) meets reinforced insulation requirements for mains-isolated circuits per IEC 60950-1 and UL 1577.