The 4N263SD is classified as Obsolete by onsemi, meaning the manufacturer has ceased production and no further factory orders are accepted. No official successor or pin-compatible replacement is recorded from onsemi.
Isolation and switching parametrics
Rated for 5300Vrms isolation — this is the withstand voltage between input LED and output phototransistor, suitable for galvanic barrier applications in industrial and telecom equipment where transient immunity is required. Minimum current transfer ratio of 20% at 10 mA forward current ensures the output transistor saturates with modest LED drive; typical turn-on and turn-off times of 2 µs each set the switching ceiling for the downstream logic input. Operating temperature range of -55°C to 100°C covers military and industrial thermal profiles — the lower bound suits avionics cold-soak conditions, while the upper limit accommodates enclosed power supplies without active cooling.
Supplied in a 6-SMD gull wing package (6-SMD, Gull Wing) with a surface-mount footprint. The gull-wing leads provide visual solder-joint inspection access and moderate standoff for conformal coating flow-under. Tape & Reel packaging (TR) indicates reel quantity suitable for automated pick-and-place assembly — the reel size and quantity are confirmed at RFQ.