Preliminary Data Sheet
October 2001
L9214A/G
Low-Cost Ringing SLIC
Introduction
The Agere Systems Inc. L9214 is a subscriber line
interface circuit that is optimized to provide a very
low-cost solution for short- and medium-loop applica-
tions. This device provides the complete set of line
interface functionality, including power ringing
needed to interface to a subscriber loop. This device
has the capability to operate with a V
CC
supply of
3.3 V or 5 V and is designed to minimize external
components required at all device interfaces.
Applications
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Voice over Internet Protocol (VoIP)
Cable Modems
Terminal Adapters (TA)
Wireless Local Loop (WLL)
Telcordia Technologies
™
GR-909 Access
Network Termination (NT)
PBX
Key Systems
Features
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Low-cost solution
Onboard ringing generation with software adjust-
able crest factor switching
Flexible V
CC
options:
— 3.3 V or 5 V V
CC
— No –5 V required
Power control options:
— Power control resistor
— Automatic battery switch to minimize off-hook
power
Eight operating states:
— Scan mode for minimal power dissipation
— Forward and reverse battery active
— On-hook transmission states
— Ring mode
— Disconnect mode
Low on-hook power:
— 25 mW scan mode
— 165 mW active mode
Two SLIC gain options to minimize external com-
ponents in codec interface
Loop start, ring trip, and ground key detectors
Programmable current limit
On-hook and scan mode line voltage clamp
Thermal protection
48-pin MLCC, 32-pin PLCC, and 28-pin SOG
(Please contact your Agere Sales Representative
for availability) packages
Description
This device is optimized to provide battery feed, ring-
ing, and supervision on short- and medium-loop plain
old telephone service (POTS) loops. Supported
round trip loop length is up to 1000
Ω
.
This device provides power ring to the subscriber by
the use of line reversal to create either a sine wave
ringing signal with a PWM input or a trapezoidal ring-
ing signal with a selectable crest factor from a square
wave input. It provides forward and reverse battery
feed states, on-hook transmission, a low-power scan
state, and a forward disconnect state.
The device requires a V
CC
and line feed battery to
operate. V
CC
may be either a 3.3 V or a 5 V supply.
The ringing signal is derived from the high-voltage
battery. An automatic battery switch is included to
allow for use of a second lower voltage battery in the
off-hook mode, thus minimizing short-loop off-hook
power consumption and dissipation. If the user
desires single battery operation, a power resistor is
required to reduce the power dissipation in the SLIC.
Loop closure, ring trip, and ground key detectors are
available. The loop closure detector has a fixed
threshold with hysteresis. The ring trip detector and
ground key detector threshold and time constants are
externally set.
The dc current limit is programmed by an external
resistor, the maximum current limit determined by the
Vcc supply.
The overhead voltage for this device is fixed and the
device is capable of supporting 3.17 dB into a 600
Ω
load with minimal overhead.
The device is offered with two gain options. This
allows for an optimized codec interface, with minimal
external components regardless of whether a first-
generation or a programmable third-generation
codec is used.
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AGERE [ AGERE SYSTEMS ]
