Obsolete — what that means for your BOM
The 4N26TM is listed as Obsolete by onsemi. Sourcing now runs through independent distribution.
Key ratings and what they mean for fit
Rated 7500Vpk isolation — this is the withstand voltage between input and output sides, tested per the device class standard. For a 230 VAC line-powered interface, that margin covers transient surges without breakdown. Minimum current transfer ratio (CTR) is 20% at 10 mA forward current. That means with 10 mA in the LED, the output transistor can sink at least 2 mA — enough to drive a logic gate input or a PLC digital input module directly. Operating temperature spans -40°C to 100°C, which covers industrial enclosures and outdoor telecom cabinets without derating.
6-DIP (0.400-inch, 10.16 mm) through-hole package — the standard 0.100-inch pitch DIP footprint. Supplied in tube packaging — not tape-and-reel, so pick-and-place requires a tube feeder or manual insertion.
Sourcing posture for the 4N26TM
As an obsolete part, the 4N26TM is sourced through independent and surplus channels. Each lot is traceable and verified for authenticity before shipment.