5000Vrms isolation in a through-hole DIP
The Renesas NEPOC PS2561DL1-1Y-H-A is a single-channel phototransistor optocoupler that provides 5000Vrms galvanic isolation between a DC input and a transistor output. It is housed in a 4-DIP through-hole package with a 0.400" (10.16mm) pin spacing, which suits industrial control interfaces, power-supply feedback loops, and medical equipment where creepage distance and isolation integrity matter more than board density.
CTR window and drive margin
The current transfer ratio is specified at 80% minimum and 160% maximum, both measured at a forward current of 5mA. That 2:1 CTR spread gives the designer a predictable gain window for sizing the pull-up resistor on the output and ensuring the logic threshold is met over temperature and device-to-device variation. A forward voltage of 1.2V typical and a maximum DC forward current of 40mA define the LED drive budget.
Output ratings and switching speed
The phototransistor output is rated for 80V maximum and 50mA continuous per channel, with a Vce saturation of 300mV maximum. Rise and fall times are 3µs and 5µs typical, which is adequate for 10-100 kHz switching in isolated gate drives or status feedback, but not intended for high-speed digital isolation above 1 Mbps.
Package and mounting reality
This is a through-hole 4-DIP package, not a surface-mount optocoupler. The 0.400" (10.16mm) body width and 2.54mm pin pitch are standard for DIP sockets or wave-solder assembly. The through-hole format is a deliberate choice: it gives a more robust mechanical anchor in high-vibration environments compared to an SOIC-4, and the longer lead length simplifies manual rework or prototyping. MSL is typically level 1 for DIP optocouplers, but confirm the moisture sensitivity on the reel label before a reflow exemption.