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 positive 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.