PBL3766 Datasheet, PDF (1/18 Pages) Ericsson – Subscriber Line Interface Circuit

September 1997
PBL 3766, PBL 3766/6
Subscriber Line
Interface Circuit
Description
The PBL 3766 Subscriber Line Interface Circuit (SLIC) is a monolithic integrated
circuit, manufactured in 75 V bipolar technology. The PBL 3766 SLIC facilitates the
design of cost effective, high performance on-premises (ONS) analog line interface
cards for PABX systems and terminal adapters. Small package size and few
required external components result in a miniaturized design.
The PBL 3766 programmable, constant current loop feed system can operate with
battery supply voltages between -24 V and -58 V.
The SLIC incorporates loop current and ring trip detection functions as well as a
ring relay driver.
The two- to four-wire and four- to two-wire voice frequency (vf) signal conversion,
i.e. the hybrid function, is provided by the SLIC in conjunction with either a conven-
tional or a programmable CODEC/filter.
The PBL 3766 package is a 22 pin, plastic dual-in-line (batwing) or a 28-pin, plastic
j-leaded chip carrier (PLCC).
The differences between PBL 3766 and PBL 3766/6 are the specifications for
balance, output offset voltage, and insertion loss.
DT 23/20
TIPX ^27/21
HPT ^20/15
HPR 21/16
RINGX 28/22
VCC 4/2
VEE 18/13
Two-wire
Interface
VBAT
GND
3, 6, 10, 17, 24/
5, 6, 17, 18
2/1
Ring Trip
Detector
Line Feed
Controller
and
Longitudinal
Signal
Suppression
Loop Current
Detector
VF Signal
Transmission
Ring Relay
Driver
Input/Output
Decoder and
Control
5/3 RINGRLY
13/10 C1
12/9 C2
9/7 E0
11/8 DET
14/11 RDC
7/4 RSG
22/19 RD
19/14 VTX
16/12 RSN
Key Features
• Low cost
• Few external components
• Programmable, constant current loop
feed
• Line feed characteristics independent
of battery supply variations
• -24 V to -58 V battery supply voltage
range
• Detectors
– programmable loop current detector
– ring trip detector
• Ring relay driver
• Hybrid function with conventional or
programmable CODEC/filters
• Line terminating impedance, complex
or real, set by a simple external
network or controlled by a
programmable CODEC/filter
• Idle noise typ. -83 dBmp, typ. 7 dBrnC
• Low on-hook power dissipation:
20 mW @ -28 V, 35 mW @ -48 V
• Tip-ring open circuit state for
subscriber loop power denial
• On-hook transmission
PBL3766
376P6BL
Figure 1. Block diagram. Pin numbers PLCC/DIP.
4-1