Product Brief
June 2000
L9215A/G
Short-Loop Sine Wave Ringing SLIC
Introduction
The L9215 is a subscriber line interface circuit that is
optimized for short-loop, power sensitive 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.
Features
■Onboard ringing generation
■Three ringing input options
— Sinewave
— PWM
— Logic level squarewave
■Flexible VCC options
— 5 V or 3.3 V VCC
— No –5 V required
■Battery switch to minimize off-hook power
■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
■Ultralow on-hook power
— 27 mW scan mode
— 41 mW active mode
■Two SLIC gain options to minimal external compo-
nents in codec interface
■Loop start, ring trip, and ground key detectors
■Software or hardware controllable current limit and
overhead voltage
■Meter pulse compatible
■32-pin PLCC package
Applications
■Voice over Internet Protocol (VoIP)
■Cable Modems
■Terminal Adapters (TA)
■Wireless Local Loop (WLL)
■
Telcordia
Technologies
* TA-909 Access
■Network Termination (NT)
■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. Supported loop length
is less than 250 Ω of wire.
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 re quire s 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.
*
Telcordia Technologies
is a registered trademark of Bell Commu-
nications Research, Inc.