OP593 and OP598 Series PhototransistorsThe OP593 and OP598 series, from Optek Technology Inc., are a family of NPN silicon phototransistors. They are in dark blue plastic TO-18 equivalent packages. They offer a wide receiving angle in a variety of different sensitivity ranges. Features of the OP593 and OP598 phototransistors:Through-hole mountingTO-18 equivalent packageDark blue lensWide receiving angleOperating temperature: -40 to +100 °CIR Phototransistors, Optek