5000Vrms isolation — the safety spec that decides the BOM
The Vishay VO615A-9X007T is a single-channel DC-input transistor-output optocoupler in a 4-SMD gull-wing package, rated for 5000Vrms isolation. The 200% to 400% current transfer ratio at 5mA forward current gives you a comfortable gain margin — the output transistor saturates reliably even when the LED ages or the temperature drifts, without needing to overdrive the input side.
Switching speed and output drive — what the timing numbers mean for the interface
Rise and fall times of 3µs and 4.7µs typical, with turn-on/turn-off times of 6µs and 5µs, place this part in the slow optocoupler class — suitable for DC-level sensing, status feedback, and low-frequency PWM up to a few kilohertz. The 50mA output current capability and 70V Vce(max) let it drive logic inputs, relay coils through an external transistor, or small loads directly. Vce(sat) of 300mV max keeps the on-state voltage drop low enough to not steal headroom from a 5V or 3.3V logic rail.
Temperature range — military-grade endurance in a commercial package
The 4-SMD gull-wing package is reflow-compatible and rated for surface-mount assembly — no through-hole insertion step, which simplifies the pick-and-place bill.