Features
1) Built-in bias resistors enable the configuration of an
   inverter circuit without connecting external input
   resistors (see equivalent circuit).
2) Each bias resistor is a thin-film resistor. Since they are
   completely insulated, the input can be negatively
   biased. The insulation also eliminates most of the
   parasitic effects.
3) Only the on / off conditions need to be set for
   operation, making device design easy.