5300Vrms isolation in a 4-SMD Gull Wing
The onsemi H11A817A3SD is a single-channel optocoupler with a DC-input LED and a phototransistor output, providing 5300Vrms of galvanic isolation between input and output circuits. Housed in a 4-SMD Gull Wing package (supplier device package 4-SMD), this surface-mount part is suited for reflow-soldered assemblies where board space is tight and isolation integrity is critical.
CTR range and switching speed for signal coupling
Current transfer ratio (CTR) is specified at 80% minimum and 160% maximum, both measured at 5mA forward current — this 2:1 spread means the output transistor's collector current is guaranteed to be at least 80% of the LED drive, so a 5mA input reliably sinks 4mA on the output side. Rise and fall times are 2.4µs typical each, which limits the practical switching frequency to roughly 100 kHz for clean pulse transmission — above that the output edges round off and the downstream logic may miss transitions. Output ratings: 50mA continuous collector current, 70V Vce maximum, and 200mV Vce saturation at rated current — this drives standard logic inputs or low-power relays directly without a buffer transistor.
onsemi has marked the H11A817A3SD as obsolete.