Features
1) Built-In Biasing Resistors, R1 = R2 = 2.2kΩ
2) Built-in bias resistors enable the configuration of
   an inverter circuit without connecting external
   input resistors (see inner circuit) .
3) Only the on/off conditions need to be set
   for operation, making the circuit design easy.
4) Complementary NPN Types: DTC123E series

Application
   INVERTER, INTERFACE, DRIVER