A PC817 Optocoupler (Photocoupler) IC is a widely used 4-pin optical isolator consisting of an Infrared Emitting Diode (IRED) optically coupled to a NPN silicon phototransistor.

This product is featured by Famephase Electronic Accessories as an essential component for switch-mode power supplies (SMPS feedback loops), AC/DC mains isolation, relay driving circuits, microcontroller I/O protection, and noise suppression in noisy industrial environments.