7500Vpk isolation in a 6-SMD gull-wing package
The onsemi H11A4FM is a single-channel phototransistor optoisolator in a 6-SMD gull-wing package, delivering 7500Vpk isolation between input and output — a rating that suits it for isolating high-voltage DC bus monitoring or AC line sensing circuits where the creepage distance across a standard DIP would be marginal. Minimum current transfer ratio is 10% at 10 mA forward current, with typical turn-on and turn-off times of 2 µs each — fast enough for 50/60 Hz zero-crossing detection and moderate-speed logic isolation, though not for high-frequency switching supplies.
Obsolete — sourcing through surplus and broker channels
onsemi lists the H11A4FM as obsolete.
Parametric floor for the bench
Forward voltage is 1.18V typical at 10 mA; maximum DC forward current is 60 mA. Vce saturation is 400 mV max — the output transistor drops less than half a volt when fully on, keeping dissipation low in a 5V logic interface. The 6-SMD gull-wing footprint is the same as a standard DIP-6 but surface-mount — reflow profile follows the solder paste manufacturer's recommendation for the package body temperature rating.