TC123YSA Datasheet - Secos Corporation.

FEATURES
* Built-in bias resistors enable the configuration of an inverter circuit without connecting input resistors
* Only the on/off confitions need to be set for operation, making device design easy.
* The bias resistors consis of thin-film resistors with compete isolation to allow negative biasing of the input. They also have the advantage of almost completely eliminating parasitic effects. (see equivalent circuit).