View dtd123tk datasheet:

Transistors Digital transistors (built-in resistor) DTD123TK / DTD123TS FFeatures FExternal dimensions (Units: mm) 1) Built-in bias resistors enable the configuration of an inverter circuit without connecting external input resistors (see equivalent circuit). 2) The bias resistors consist of thin- film resistors with complete isola- tion to allow negative biasing of the input. They also have the advan- tage of almost completely eliminat- ing parasitic effects. 3) Only the on/off conditions need to be set for operation, making device design easy. FStructure NPN digital transistor (Built-in resistor type) FAbsolute maximum ratings (Ta = 25_C) FEquivalent circuit (96-368-D123T) 456 Transistors DTD123TK/DTD123TS FElectrical characteristics (Ta = 25_C) FPackaging spec