Lifecycle reality — obsolete, but sourced
The H11A23S is formally marked obsolete by onsemi (product status: Obsolete).
Isolation and switching profile
Rated at 5300 Vrms isolation, this optoisolator provides reinforced isolation for safety-critical galvanic barriers in industrial power supplies, motor drive feedback, and PLC digital input modules — the 5300 Vrms figure covers the 250 V working voltage with headroom for transient overvoltage per IEC 60950-1 reinforced insulation requirements. The single-channel DC input drives a phototransistor with base access. Minimum current transfer ratio is 20% at 10 mA forward current, ensuring the output can be pulled low enough to register a logic-level change even with modest LED drive current across the isolation barrier. Switching is specified at 2 µs turn-on and 2 µs turn-off typical — fast enough for 100 kHz class switching power supply feedback loops and serial data isolation up to 250 kbps. The Vce(sat) clamp at 400 mV max means the output transistor pulls within 0.4 V of the emitter rail at rated drive, keeping the logic-low threshold well within TTL or 3.3 V CMOS input specs.
Board integration and temperature grade
Housed in a 6-SMD gull-wing package (6-SMD, Gull Wing per; supplier device package 6-SMD per), this surface-mount optoisolator mates to a standard 6-pin DIP footprint with a 7.62 mm pitch — no lead forming needed for reflow. The -55 °C to 100 °C operating range covers industrial and outdoor telecom enclosure ambient temperatures, though the junction temperature must stay derated when forward current approaches the 100 mA absolute maximum. The 30 V output max (Vce) accommodates common 24 V industrial logic rails and 12 V auxiliary supplies. The base pin access allows external base resistor adjustment for switching speed optimisation or Miller clamp in noise-sensitive circuits.