PBL 387 73/1
Subscriber Line
Interface Circuit (SLIC)
Key Features
• On-chip ringing generation
- Balanced, up to 81 V
Peak
- Any waveform
- 5REN ringing load
- Automatic gain control of ring signal (AGC-R)
- Short circuit safe
• Low on-hook power consumption in Active
State (65 mW @ V
Bat
= -80 V)
• Automatic current controlled battery
switching between on-hook battery (V
Bat
) and
talk battery (V
TBat
)
• Pulse metering and on-hook transmission
• UL-1950 and MTU compliant on-hook line
voltage
• 3.3 V compatible logic interface
• Programmable Ring-Trip current
VTB
Ringing
Control
CRING
VR
VTBAT
VBAT
BGND
Ring Trip
Detector
VCC
AGND
PRT
C1
C2
Input
Decoder and
Control
TIPX
HP
C3
DET
RINGX
Two-wire
Interface
Line Feed
Controller
PLC
LP
REF
and
Longitudinal
Signal
Suppression
Off-hook
Detector
PLD
VTX
RSN
VF Signal
Transmission
Figure 1. Block diagram.
Description
The ringing FlexiSLIC™ PBL 387 73/1 Subscriber Line
Interface Circuit (SLIC) is a 90 V bipolar integrated cir-
cuit for use in short loop applications. The PBL 387 73/1
SLIC has been optimized for low power consumption,
low total line interface cost and for a high degree of
flexibility in various applications.
The PBL 387 73/1 SLIC supplies a balanced, sinewave
or trapezoidal ringing signal of up to 81 V
Peak
(85 V
DC supply) to the subscriber line across a load of up
to 5REN. The PBL 387 73/1 supplies programmable
constant current to the subscriber loop, sourced from
the talk battery. The On-Hook line voltage of 43 V to
56 V is derived from the battery. All battery switching
is internal to the device and is automatic. To further
reduce power consumption the automatic gain control
for the ring signal (AGC-R) keeps the level always
adjusted to the maximum, that can be sourced from the
available battery.
The SLIC incorporates loop current and ring-trip
detection functions. The PBL 387 73/1 is compatible
with loop start and ground start signalling. Two-
to four-wire and four- to two-wire voice frequency
(vf) signal conversion is accomplished by the SLIC in
conjunction with a standard codec. The line terminat-
ing impedance and balance impedance is program-
mable and may be complex or real for worldwide
compliance.
Longitudinal balance specifications and other device
characteristics are in compliance with Telcordia (Bell-
core) and ITU-T requirements.
Tip and ring voltages are UL-1950 compliant;
i.e. no two-wire line voltage exceeds 56 V. The
PBL 387 73/1 SLIC is packaged in a surface mount
28-pin SOIC package.
ERICSSON [ ERICSSON ]
