The CNY172VM: The 4170 Vrms isolation rating qualifies this optoisolator for reinforced isolation between mains-powered and low-voltage circuits — think PLC digital inputs, motor drive feedback, or medical patient-interface barriers where the creepage and clearance of a 6-DIP package (0.300-inch lead spacing) meet IEC 60950-1 reinforced insulation for 250 V working voltage. Current transfer ratio spans 63% minimum to 125% maximum at 10 mA forward current — a wide enough window that the logic threshold on the output side stays well-defined without requiring tight binning of the LED. The transistor-with-base output lets you add an external base resistor to trade switching speed against gain, useful when driving a slow opto-coupler into a fast PLC input. Rise and fall times are 4 µs and 3.5 µs typical respectively, with turn-on at 2 µs and turn-off at 3 µs — adequate for 100 kHz data rates but not for high-speed isolated communication like I²C or CAN. The 70 V output breakdown and 50 mA continuous output current cover most logic-level and low-power relay drive applications.
The base part number CNY172 covers multiple CTR and packaging variants; the VM suffix denotes the tube-packaged, ROHS3-compliant version.
Package and temperature grade
The 7.62 mm row spacing provides adequate creepage for the 4170 Vrms rating; keep the copper keep-out zone under the body per the recommended PCB layout to maintain isolation distance.