2500Vrms isolation in a 4-SSOP — what it buys you
The Renesas PS2805C-1-F3-A is a single-channel phototransistor optocoupler from the NEPOC series, packing 2500Vrms of galvanic isolation into a 4-SSOP surface-mount package. It accepts both AC and DC input on the LED side, which simplifies polarity-insensitive designs — handy when the input comes from a bipolar sensor or a relay contact that might swing either way.
CTR spread: 50% to 400% at 5mA forward current
The current transfer ratio spans 50% minimum to 400% maximum, tested at 5mA LED current.
Switching speed — this is not a high-speed isolator
Rise time is 5µs typical, fall time 7µs typical. Turn-on is 10µs, turn-off 7µs.
Comes in a 4-SOIC (0.173", 4.40mm width) package, also called 4-SSOP in the supplier device package field. Surface-mount only. The LED anode and cathode are on one side, the transistor collector and emitter on the other — orientation is obvious from the package marking, so a field swap with a hot-air station is doable if you have the kit. No exposed pad, no thermal via stitching needed.