The CNY172TM is listed as Obsolete by onsemi, meaning the manufacturer has discontinued production. This part is sourced to order through independent distribution channels.
Isolation rating and switching performance
Rated for 4170Vrms isolation, the CNY172TM provides reinforced insulation suitable for mains-isolated feedback, motor-drive gate drive, and industrial sensor interfaces where safety isolation is required. Switching speeds of 2 µs turn-on and 3 µs turn-off (typical), with 4 µs rise and 3.5 µs fall times, position this optocoupler for moderate-speed digital signals — PLC input modules, relay drivers, and logic-level translation up to a few hundred kilohertz.
Current transfer ratio and drive margins
The CTR range of 63% to 125% at 10 mA forward current gives the designer a known spread to budget for LED aging and temperature drift. At the minimum CTR, a 10 mA LED drive yields at least 6.3 mA collector current — enough to saturate a downstream logic gate or relay coil with margin. Maximum forward current is 60 mA, and the output transistor can sink up to 50 mA continuous at 70 V Vce — adequate for driving small relays, opto-isolated solid-state switches, or level-shifting 5 V logic to 24 V industrial rails.
Housed in a 6-DIP package with 0.400-inch (10.16 mm) lead spacing, the CNY172TM fits standard through-hole PCB layouts. The supplier device package is 6-DIP, identical to the package/case — no footprint variation. The DC input type and transistor-with-base output are the classic phototransistor topology, compatible with most common optocoupler drive circuits.