PBL38610-2

February 1999 PBL 386 10/2 Subscriber Line Interface Circuit Description The PBL 386 10/2 Subscriber Line Interface Circuit (SLIC) is a 90 V bipolar integrated circuit for use in PBX, Terminal adapters and other telecommunications equipment. The PBL 386 10/2 has been optimized for low total line interface cost and a high degree of flexibility in different applications. The PBL 386 10/2 emulates a transformer equivalent dc-feed, programmable between 2x25 Ω and 2x900 Ω, with short loop current limiting adjustable to max 65 mA. A second lower battery voltage may be connected to the device to reduce short loop power dissipation. The SLIC automatically switches between the two battery supply voltages without need for external components or external control. The SLIC incorporates loop current, ground key and ring trip detection functions. The PBL 386 10/2 is compatible with loop start signalling. 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. Longitudinal line voltages are suppressed by a feedback loop in the SLIC and the longitudinal balance specifications meet Bellcore TR909 requirements. The PBL 386 10/2 package is 28-pin PLCC. Key Features Selectable overhead voltage principle – All adaptive: The overhead vo...