The H11A2SD is marked Obsolete by onsemi. No official successor is listed — the part is sourced through independent distribution against an RFQ.
Isolation and switching performance
Rated for 5300Vrms isolation — this is the reinforced insulation class for mains-referenced circuits in industrial PSUs, motor drives, and PLC digital inputs where the primary-secondary barrier must hold off transient overvoltages per IEC 60950-1. Minimum CTR of 20% at 10 mA forward current means the output transistor saturates with a 2 mA collector load — enough to drive a TTL or 5 V CMOS gate without a buffer stage. Typical turn-on and turn-off times are 2 µs each — the part handles 250 kbps data rates cleanly, suitable for status feedback or low-speed isolated serial links.
Operating from -55°C to 100°C, the H11A2SD covers industrial and some military/aerospace ambient conditions — the 100°C ceiling is the junction limit, so derating applies above 85°C ambient. Housed in a 6-SMD gull wing package (6-SMD supplier device package), it sits on the same footprint as the standard DIP-6 but reflow-soldered — the gull wing leads absorb board flex better than J-bend in high-vibration environments.