Preliminary Information
February 2000
PBL 386 14/1
Subscriber Line
Interface Circuit
Description
The PBL 386 14/1 Subscriber Line Interface Circuit (SLIC) is a 90 V bipolar integrated
circuit for use in ISDN Network Terminal Adapters and other short loop
telecommunication equipment which often are remote powered, and by that, the
available power is limited. The PBL 386 14/1 has been optimized for low total line
interface cost, low power and requires a minimum of external components.
The PBL 386 14/1 has constant current feed, programmable to max 30mA. The SLIC
uses a first battery voltage for On-hook . A second battery voltage is used for
Off-hook and must be connected, 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 loop current controls the switching
between On-hook and Off-hook battery.
The SLIC incorporates loop current, ground key and ring trip detection functions.
The PBL 386 14/1 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 voltages are
suppressed by a feedback loop in the SLIC and the longitudinal balance specifica-
tions meet Bellcore TR909 requirements.
The PBL 386 14/1 package is a very PCB space efficient 28-pin SSOP.
Applications
• ISDN Network terminals
• Shortloop applications
Key Features
• Small footprint with SSOP package
• On-hook and Off-hook battery with
automatic switching, controlled by
loop current
• On-hook battery current is limited
to 6 mA
• 37 mW on-hook power dissipation in
active state
• Metering 0.5 Vrms (0.7 Vpeak)
• Adaptive Overhead Voltage
The overhead voltage follows
1Vpeak<signals<2.5Vpeak
• Battery supply as low as -10V
• Only +5V in addition to GND
and battery (VEE optional)
• Open loop voltage tracks On-hook
battery
• Full longitudinal current capability
during On-hook
• 43.5V open loop voltage @ -48V
battery feed
• Automatic compensation for
line leakage up to 5 mA
• On-hook transmission
• Programmable loop & ring-trip
detector threshold
• Ground key detector
• Analog temperature guard with status
exclusively viewed at detector output
• Integrated Ring Relay Driver
• Linevoltage measurement
Ring Relay
Driver
DT
DR
TIPX
RINGX
HP
TS
RRLY
Ring Trip
Comparator
Input
Decoder and
Control
C1
C2
C3
VCC
DET
Ground Key
Detector
Two-wire
Interface
Line Feed
Controller
and
Longitudinal
Signal
Suppression
PSG
LP
REF
PLC
VBAT2
VBAT
Off-hook
Detector
PLD
AGND
VTX
BGND
VF Signal
Transmission
RSN
VEE
(optional)
P
/1
6 14
8
BL 3
Figure 1. Block diagram.
Package: 28-pin SSOP
1
ERICSSON [ ERICSSON ]
