L9216A Datasheet, PDF (1/48 Pages) Agere Systems – Short-Loop Ringing SLIC with Ground Start

Preliminary Data Sheet
September 2001
L9216A/G
Short-Loop Ringing SLIC with Ground Start
Introduction
The Agere Systems Inc. L9216 is a subscriber line
interface circuit (SLIC) that is optimized for short-
loop, power-sensitive applications. This device pro-
vides the complete set of line interface functionality,
including power ringing needed to interface to a sub-
scriber 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.
Applications
s Voice over Internet Protocol (VoIP)
s Cable Modems
s Terminal Adapters (TA)
s Wireless Local Loop (WLL)
s Telcordia Technologies™ GR-909 Access
s Network Termination (NT)
s Key Systems
Features
s Onboard ringing generation
s Three ringing input options:
— Sine wave
— PWM
— Logic level square wave
s Flexible VCC options:
— 5 V or 3.3 V VCC
— No –5 V required
s Battery switch to minimize off-hook power
s Eight operating states:
— Scan mode for minimal power dissipation
— Forward and reverse battery active
— On-hook transmission states
— Ground start (tip open)
— Ring mode
— Disconnect mode
s Ultralow on-hook power:
— 27 mW scan mode
— 41 mW active mode
s Two SLIC gain options to minimal external compo-
nents in codec interface
s Loop start, ring trip, and ground start detectors
s Software-controllable dual current-limit option
s 28-pin PLCC package
s 48-pin MLCC package
Description
This device is optimized to provide battery feed, ring-
ing, and supervision on short-loop plain old tele-
phone service (POTS) loops.
This device provides power ring to the subscriber
loop through amplification of a low-voltage input. It
provides forward and reverse battery feed states, on-
hook transmission, a low-power scan state, ground
start (tip open), and a forward disconnect state.
The device requires a VCC and battery to operate.
VCC may be either a 5 V or a 3.3 V supply. The ring-
ing signal is derived from the high-voltage battery. A
battery switch is included to allow for use of a lower-
voltage battery in the off-hook mode, thus minimizing
short-loop off-hook power.
Loop closure, ring trip, and ground start detectors are
available. The loop closure detector has a fixed
threshold with hysteresis. The ring trip detector
requires a single-pole filter, thus minimizing external
components required.
The dc current limit is set and fixed by a logic control-
lable pin. Ground or open is applied to this pin set the
current limit at the low or high value.
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.