Single-channel optocoupler with AC/DC input — 5000 Vrms isolation in a 4-pin DIP
The Renesas PS2565-1Y-A is a single-channel phototransistor optocoupler in a 4-DIP through-hole package. The output is a standard phototransistor rated for 50 mA continuous and 80 V across the collector-emitter.
5000 Vrms isolation — what it buys you in the BOM
The 5000 Vrms isolation rating is the headline safety parameter. It provides reinforced insulation for power-supply feedback loops, motor-drive interface circuits, and any design where the primary and secondary sides must be galvanically separated for regulatory compliance. The 4-DIP package with 7.62 mm pin pitch gives enough creepage for most industrial and medical applications without needing a wider-body part.
CTR spread: 80 % to 400 % at 5 mA — biasing for the minimum
The current transfer ratio spans 80 % minimum to 400 % maximum, both specified at 5 mA forward current. That is a 5:1 spread across units. The designer must size the pull-up resistor and the downstream logic threshold for the 80 % floor; the 400 % ceiling means the output saturates harder at the same drive, which is harmless as long as the collector current stays under the 50 mA absolute maximum. For procurement, this wide CTR bin means the part is less tightly screened than a narrow-CTR grade — acceptable for general-purpose isolation, but if you need a predictable Vce(sat) over temperature, you may want a tighter-sorted alternative.
Temperature range and environment
Rated for -55°C to 100°C operating ambient. That covers the full industrial temperature band and extends into cold-start environments down to -55°C — think outdoor telecom cabinets, engine-bay-adjacent sensors, and military-grade ground equipment. The 100°C upper limit is the junction or ambient spec (the datasheet typically states operating temperature, not case); if the design runs the LED near the 80 mA absolute maximum in a warm enclosure, derate the forward current to keep junction temperature inside the limit.
The through-hole DIP package also means it is straightforward to hand-assemble or rework in prototype runs.