DATASHEET 4PIN DIP PHOTOTRANSISTOR PHOTOCOUPLER EL817 Series Device MarkingEL817FRYWWVNotes EL denotes EVERLIGHT 817 denotes Device Number F denotes Factory Code (G: China and Green part) R denotes CTR Rank (A, B, C, D , X , Y or none) Y denotes 1 digit Year code WW denotes 2 digit Week code V denotes VDE (optional)