Preliminary Data Sheet
October 2001
L9214A/G
Low-Cost Ringing SLIC
Applications
Introduction
■ Voice over Internet Protocol (VoIP)
■ Cable Modems
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 VCC supply of
3.3 V or 5 V and is designed to minimize external
components required at all device interfaces.
■ Terminal Adapters (TA)
■ Wireless Local Loop (WLL)
■ Telcordia Technologies™ GR-909 Access
■ Network Termination (NT)
■ PBX
■ Key Systems
Features
■ Low-cost solution
Description
■ Onboard ringing generation with software adjust-
able crest factor switching
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.
■ Flexible VCC options:
— 3.3 V or 5 V VCC
— No –5 V required
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.
■ 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
The device requires a VCC and line feed battery to
operate. VCC 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.
— 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 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.
■ Loop start, ring trip, and ground key detectors
■ Programmable current limit
■ On-hook and scan mode line voltage clamp
■ Thermal protection
The dc current limit is programmed by an external
resistor, the maximum current limit determined by the
Vcc supply.
■ 48-pin MLCC, 32-pin PLCC, and 28-pin SOG
(Please contact your Agere Sales Representative
for availability) packages
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.
AGERE [ AGERE SYSTEMS ]
