7500Vpk isolation — obsolete, sourced per RFQ
The onsemi CNY172FM is a 1-channel optoisolator with a DC input and a transistor-with-base output. Its headline rating is 7500Vpk isolation — this is the transient-withstand voltage between input and output, certified for applications where galvanic separation must survive high-voltage spikes across the barrier. The current transfer ratio (CTR) spans 63% to 125% at a forward current of 10 mA. This range tells you the output transistor's current gain under the test condition — a CTR of 63% means the collector current will be at least 6.3 mA when the LED is driven at 10 mA, which sets the minimum load the output can sink without saturating. onsemi has marked the CNY172FM as obsolete.
Switching speed and output ratings
Rise and fall times are 1 µs and 2 µs typical; turn-on and turn-off times are 2 µs and 3 µs typical. These figures define the maximum data rate through the opto — at 3 µs off-time the practical switching frequency is around 160 kHz, adequate for isolating slow digital signals, PLC inputs, or relay-drive commands. The output transistor is rated for 70 V maximum collector-emitter voltage and 50 mA continuous current. The 400 mV Vce saturation at that current keeps the voltage drop low enough to drive a 5 V logic input without an extra pull-up resistor. Forward voltage is 1.35 V typical at the LED; maximum forward current is 60 mA.
6-SMD gull wing — board-fit note
The CNY172FM comes in a 6-SMD gull-wing package (supplier device package 6-SMD), surface-mount on a standard 2.54 mm pitch footprint. The gull-wing leads are solder-inspectable and reworkable with a hot-air station — no bottom-side pad alignment needed. Supplied in Tube packaging, which is the standard anti-static tube for hand-loading or automated tube feeders. The base product number is CNY172, indicating this is the gull-wing variant of the through-hole CNY17 family.