4170Vrms isolation in a 6-SMD gull wing
The onsemi CNY173SR2M is a single-channel phototransistor optoisolator in a 6-SMD gull wing package, delivering 4170Vrms of galvanic isolation between a DC input LED and a transistor-with-base output. This isolation rating suits it for breaking ground loops and protecting low-voltage logic from high-side transients in industrial control, motor drive, and power supply feedback paths.
CTR window and switching response
Turn-on and turn-off times are 2µs and 3µs typical, with rise and fall times of 4µs and 3.5µs max. This places the CNY173SR2M in the medium-speed class for phototransistor isolators — fast enough for 100kHz PWM feedback or serial status polling, but not for high-speed data links where a digital isolator would be needed. The output transistor can sink up to 50mA continuous with a maximum Vce saturation of 400mV, and the collector-emitter breakdown is rated at 70V. This means it can directly drive a small relay coil, a PLC input, or a 24V logic gate without a secondary buffer transistor.
The base product number is CNY173, and the SR2M suffix denotes the Tape & Reel packaging option for automated pick-and-place assembly.