The Intersil SLIC incorporates many of the BORSHT functionson a single IC chip. This includes DC battery feed, a ring relaydriver, supervisory and hybrid functions. This device isdesigned to maintain transmission performance in thepresence of externally induced longitudinal currents. Usingthe unique Intersil dielectric isolation process, the SLIC canoperate directly with a wide range of station battery voltages.The SLIC also provides selective denial of power. If the PBXsystem becomes overloaded during an emergency, the SLICwill provide system protection by denying power to selectedsubscriber loops.The Intersil SLIC is ideally suited for the design of new digitalPBX systems by eliminating bulky hybrid transformers.