L9215A Datasheet, PDF (1/50 Pages) Agere Systems – Short-Loop Sine Wave Ringing SLIC

Data Sheet
September 2001
L9215A/G
Short-Loop Sine Wave Ringing SLIC
Introduction
The Agere Systems Inc. L9215 is a subscriber line
interface circuit that is optimized for short-loop,
power-sensitive applications. This device provides
the complete set of line interface functionality (includ-
ing 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 mini-
mize external components required at all device
interfaces.
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 11 operating states:
— Scan mode for minimal power dissipation
— Forward and reverse battery active
— On-hook transmission states
— Meter pulse states
— Ring mode
— Disconnect mode
s Ultralow on-hook power:
— 27 mW scan mode
— 42 mW active mode
s Two SLIC gain options to minimal external compo-
nents in codec interface
s Loop start, ring trip, and ground key detectors
s Software- or hardware-controllable current-limit
and overhead voltage
s Meter pulse compatible
s 32-pin PLCC package
s 48-pin MLCC package
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
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, meter
pulse states, 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 key 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.
This device supports meter pulse applications. Meter
pulse is injected into a dedicated meter pulse input.
Injection of meter pulse onto tip and ring is controlled
by the device’s logic input pin.
Both the dc current limit and overhead voltage are
programmable. Programming may be done by exter-
nal resistors or an applied voltage source. If the volt-
age source is programmable, the current limit and
overhead may be set via software control.
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.