Features
1) Built-in bias resistors enable the configuration of an inverter
   circuit without connecting external input resistors (see the
   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 the device design easy.

Structure
   NPN epitaxial planar silicon transistor
   (Resistor built-in type)