PBL 386 10/2
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
with short loop current limiting adjustable to max
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.
• Selectable overhead voltage principle
– All adaptive: The overhead voltage
follows 0.6 V
< signals < 5 V
– Semi adaptive: The overhead voltage
follows 2.5 V
< signals < 5 V
• Metering 1.6V
• High and low battery with automatic
• Battery supply as low as -10V
• Only +5V in addition to GND
and battery (VEE optional)
• 35 mW on-hook power dissipation in
• Long loop battery feed tracks V
maximum line voltage
• 44V open loop voltage @ -48 V battery
• Constant loop voltage for line
leakage <5 mA
• On-hook transmission
• Full longitudinal current capability
• Programmable loop & ring-trip detector
• Ground key detector
• Analog temperature guard
• Integrated Ring Relay Driver
Figure 1. Block diagram.
28-pin plastic PLCC