Features
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 isolation to allow negative biasing of
   the input. They also have the advantage of almost completely eliminating parasitic effects.
3) Only the on/off conditions need to be set for operation, making device design easy.

Structure
   NPN digital transistor(Built-in resistor type)