The Renesas PS8101-F3-AX is a single-channel transistor-output optocoupler from the NEPOC series, delivering 3750Vrms of galvanic isolation in a 5-pin 5-SOP surface-mount package. The single-channel configuration with a DC input and transistor output is the workhorse topology for isolated digital signals, PLC I/O, motor-drive feedback, and switch-mode power-supply feedback loops.
CTR range and switching speed — the design margins
The current transfer ratio (CTR) is specified as 15% minimum and 35% maximum at a forward current of 16mA. Switching speed is specified as 500ns typical turn-on and 600ns typical turn-off.
Temperature range and package rework
The 100°C upper limit is the ambient — junction temperature will be higher due to self-heating from the LED and output transistor, so check the derating if running near max forward current (25mA) at high ambient. That 5-pin layout is specific — make sure your footprint matches the 5-pin SOP pattern, not a standard 6-pin SOIC.
No official replacement or successor is listed, and no pin-compatible second source is documented.