The Vishay VO615A-7X009T is a single-channel optocoupler with a DC input LED driving a phototransistor output. The transistor output can switch up to 70V and sink 50mA continuous, which covers most logic-level interface and feedback paths.
Current transfer ratio and switching speed
The CTR is 80% minimum and 160% maximum at 5mA forward current.
The part comes in a 4-SMD package with gull-wing leads. That footprint is straightforward to hand-solder or rework with a hot-air station — the leads are visible and accessible, unlike a QFN or BGA. The gull-wing profile also gives some compliance for thermal cycling on the board. The tape-and-reel or cut-tape options cover both prototype and production volume.