PC817XNNSZ0F Series contains an IRED optically coupled to a phototransistor. It is packaged in a 4-pin DIP. Input-output isolation voltage(rms) is 5kV. Collector-emitter voltage is 80V
PC817. PC -817 is also known as an optocoupler. It consists of and Infra Red Emitting Diode (IRED). This IRED is coupled to a photo transistor optically and not electrically. It is closed in a four (4) pin package. This package is usually available in two different forms. The first one is wide lead (Pb) spacing option and the second one is SMT gullwing lead form option.
Optocouplers can be used to isolate low-power circuits from higher power circuits and to remove electrical noise from signals. Optoisolators are most suited to digital signals but can also be used to transfer analog signals.