The onsemi CNY173FVM is a 1-channel optoisolator with a DC input LED and a phototransistor output that brings the base terminal out — a detail that matters if your circuit uses base bias or a speed-up network. The 7500Vpk isolation rating means it can withstand repeated high-voltage transients across the isolation barrier, making it a candidate for line-voltage monitoring or motor-drive feedback where common-mode surges are a given. The current transfer ratio (CTR) spans 100% to 200% at a 10 mA forward current — a tight enough window that the logic threshold at the receiver side stays predictable without a lot of gain margin. Switching is spec'd at 1 µs rise and 2 µs fall typical, with turn-on and turn-off times of 2 µs and 3 µs typical, which keeps the part usable for 100 kHz-class isolation links.
The CNY173FVM comes in a 6-SMD gull wing package — the same footprint as the standard DIP-6 surface-mount optoisolator. The supplier device package is 6-SMD, and the part ships in tube. The 400 mV Vce saturation max and 50 mA continuous output current mean the phototransistor side can drive a logic input or a small relay directly, but the 70 V output max sets the collector rail ceiling. Operating temperature is -40°C to 100°C — industrial grade, so the part holds its CTR and switching speed across a factory-floor ambient range. The forward voltage is 1.35 V typical, and the LED can be driven up to 60 mA continuous.