What this NEPOC optocoupler is and where it goes
The Renesas PS8501L3-AX is a single-channel DC-input optocoupler from the NEPOC series, delivering 5000Vrms of galvanic isolation in an 8-SMD gull wing package. It uses a phototransistor with a base connection for the output, giving you the option to bias the base for faster switching or lower leakage — handy when you need to tune the response in a motor drive or industrial PLC input.
Turn-on time of 220ns and turn-off of 350ns are quick for a phototransistor opto. That matters if you are isolating a digital signal like an encoder pulse train or a PWM gate drive — you get clean edges without adding a Schmitt trigger on the output. At 8mA output per channel, this part handles standard logic loads like a microcontroller input or a relay driver directly.
The gull wing leads are visible for inspection, which is a plus for rework in the field — you can see the solder joint. The 8-SMD footprint is common across the NEPOC family, so swapping between single-channel variants in layout is straightforward if the BOM changes.
No official successor or second-source cross is recorded in the NEPOC line for this specific order code, but the PS2801C-4-V-A is a four-channel sibling with similar isolation and transistor output — useful if you need channel density and can accept a 2500Vrms isolation rating instead of 5000Vrms.