The CNY171300 is listed as Obsolete by onsemi, meaning the manufacturer has discontinued production. This is a single-channel optocoupler in a 6-DIP through-hole package, rated for 5300Vrms isolation — a standard spec for industrial isolation barriers in power supplies, motor drives, and PLC digital inputs.
Key ratings and what they mean for the BOM
Current transfer ratio (CTR) is guaranteed between 40% and 80% at 10 mA forward current — this band is typical for general-purpose optocouplers and ensures the output transistor saturates reliably when driving a logic input or a low-current relay coil. The output transistor handles up to 70 V collector-emitter and 50 mA continuous current, with a 300 mV saturation voltage at rated drive — sufficient for 5 V or 24 V logic-level interfaces in industrial control. Switching speed is modest: 1 µs rise, 2 µs fall typical, with turn-on/turn-off times of 2 µs and 3 µs respectively. This limits the part to signals below about 100 kHz — fine for 50/60 Hz line sync or slow PLC inputs, not for high-speed data isolation. Operating temperature spans -55°C to 100°C, covering industrial and some military/aerospace environments. The 5300Vrms isolation rating meets reinforced insulation requirements per IEC 60950-1 for mains-connected equipment.
The 6-DIP footprint is shared across many optocouplers, so a board layout designed for a similar part may accept this one without a spin.