Lifecycle reality for the BOM line
The H11A4SR2M is listed as Obsolete by onsemi. This means the manufacturer has ceased production and there is no official last-time-buy window remaining.
Isolation and switching parametrics
Rated for 7500Vpk isolation, this optoisolator suits applications requiring reinforced insulation between a low-voltage DC control side and a higher-voltage output stage — for example, in power supply feedback loops or industrial sensor interfaces where galvanic separation is mandatory. With a minimum current transfer ratio of 10% at 10 mA forward current, the input LED must be driven with at least 10 mA to guarantee the output transistor switches on. Typical turn-on and turn-off times are 2 µs each, placing the part in the medium-speed range — adequate for 50/60 Hz line-frequency isolation and general-purpose logic-level translation, but not for high-speed data links. The output transistor handles up to 30 V collector-emitter with a saturation voltage of 400 mV max, so the load side can interface directly with 5 V or 24 V logic families without an extra level shift, provided the pull-up resistor is sized for the available collector current.
Supplied in a 6-SMD gull wing package for surface mount assembly. The supplier device package is listed as 6-SMD, and the tape and reel format supports automated pick-and-place.