Phototransistors Come With Integrated Resistors

The OP793 and OP798 silicon NPN phototransistors with integrated base-emitter resistors have a low current roll-off characteristic that lets the phototransistor ignore low-level lighting while providing sharp turn-on characteristics in low contrast applications. For example, the presence of a transparent material can cause only a slight variation in a standard phototransistor's output current, while the base-emitter phototransistor's output is sharply different, an easily detectable current difference. The OP793 has a wide 130° acceptance angle while the OP798 has a narrow 25° acceptance angle.