PBL38710-1

February 1999 PBL 387 10/1 Subscriber Line Interface Circuit Description The PBL 387 10/1 ring SLIC (Subscriber Line Interface Circuit) is a bipolar integrated circuit in 90 V technology which replaces the conventional transformer based analog line interface and ringrelay in FITL, WLL, ISDN-TA and other telecommunications equipment with a modern, compact solid state design. Not only is required PCB area reduced, but less component weight and height result as well. The PBL 387 10/1 has been optimized for low cost and to require only a minimum of external components. The PBL 387 10/1 constant-current feed system, programmable to max 40 mA of line current, can operate with battery supply voltages down to -21 V to reduce line card power dissipation. The SLIC incorporates loop current, ground key and ring trip detection functions. Two-to four-wire and four- to two-wire voice frequency (vf) signal conversion is accomplished by the SLIC in conjunction with either a conventional CODEC/filter or with a programmable CODEC/filter (e.g. SLAC, SiCoFi, Combo II). The programmable line terminating impedance could be complex or real to fit every market. The PBL 387 10/1 package is 28-pin PLCC. Key Features · Ring SLIC eliminates ring relay and conventional ring-generator · Supports sine wave and trapezoidal ringing · -85 V battery feed for high voltage ring signal · On chip automatic battery switch · Programmable battery feed characteristics · Battery supply voltage as low as -21 V for pow...