Single-channel 5000Vrms isolation — what it buys you
The Renesas PS8502-AX is a single-channel optoisolator from the NEPOC series, built for galvanic isolation in industrial and power-conversion circuits. Its headline rating is 5000Vrms isolation between input and output, which covers reinforced-insulation requirements for motor-drive feedback, PLC digital inputs, and medical-grade power supplies where a single fault must not create a shock hazard. The transistor output delivers up to 8mA per channel with a 35V collector-emitter ceiling, so it can directly drive a logic gate input or a small relay coil without a buffer transistor.
220ns turn-on, 350ns turn-off — timing budget for isolated feedback
Switching times of 220ns turn-on and 350ns turn-off typ at 16mA forward current place this part in the fast side of standard transistor-output optos. That speed lets it pass a 1 MHz PWM signal with acceptable edge degradation, which matters when the part is used in isolated gate-drive feedback for IGBT/MOSFET switching stages or in isolated ADC sampling triggers. The 1.7V typical forward voltage is on the low side for a 5V logic rail, so the LED can be driven directly from a 3.3V or 5V GPIO through a current-limiting resistor sized for the 16mA test point.
Temperature range and package — where it goes
Rated from -55°C to 100°C operating, the PS8502-AX is comfortable in outdoor telecom cabinets, factory-floor enclosures, and engine-bay electronics where commercial-grade parts would drift or latch. The 8-DIP through-hole package (0.300" body width) is a legacy-friendly footprint — easy to hand-assemble, rework, or socket in a prototype — and the 7.62mm pin pitch matches standard perfboard and DIP sockets. Through-hole also helps with creepage distance on the PCB: the 8-DIP body gives natural spacing between primary and secondary sides when the part bridges a safety isolation barrier.