The onsemi CNY17F3SVM is a single-channel optoisolator in a 6-SMD Gull Wing package, combining a DC-input LED with a phototransistor output. It provides 4170Vrms galvanic isolation between input and output circuits. The current transfer ratio (CTR) is specified at 100% minimum and 200% maximum when the forward current is 10mA — this binning ensures consistent gain across the lot, which matters when the output must saturate a logic input or drive a relay coil without extra gain stages. Operating temperature spans -40°C to 100°C, covering industrial control cabinets and outdoor telecom enclosures where the ambient can swing beyond commercial limits.
Output drive and switching speed
The phototransistor output is rated for 70V maximum collector-emitter voltage and can sink 50mA continuous per channel — enough to drive a small relay, a PLC digital input, or a level translator. Saturation voltage is clamped at 400mV max, keeping the logic-low threshold well below TTL/CMOS input specs. Typical turn-on time is 2µs and turn-off time is 3µs, with rise/fall times of 4µs and 3.5µs respectively. This places the usable switching frequency in the low tens of kilohertz — adequate for 50/60Hz line sensing, status feedback, and slow serial isolation, but not for high-speed data links. Forward voltage is 1.35V typical at rated current, and the LED can handle up to 60mA DC forward current — the 10mA test condition for CTR leaves margin for derating over temperature or driving from a 3.3V logic rail through a series resistor.
onsemi has marked the CNY17F3SVM as Obsolete. The 6-SMD Gull Wing footprint is common across the CNY17 family, so a functional equivalent from the same series (with matching CTR bin and isolation rating) may be a drop-in candidate — verify the pinout and CTR bin before committing a board spin.