L9312 Datasheet, PDF (1/40 Pages) Agere Systems – Line Interface and Line Access Circuit Forward Battery SLIC and Ringing Relay for TR-57 Applications

Data Sheet
July 2001
L9312 Line Interface and Line Access Circuit
Forward Battery SLIC and Ringing Relay for TR-57 Applications
Introduction
The Agere Systems Inc. L9312 is a combination full-
feature, ultralow-power SLIC, and solid-state ringing
access relay. It is part of a pin-for-pin compatible
family of devices designed to serve a wide variety of
applications. The L9312 is optimized for TR-57
access, forward battery only, applications.
Features
SLIC
s 5 V and battery operation
s Optional automatic battery switch
s Four operational modes
s Appropriate for 58 dB longitudinal balance applica-
tions
s Minimal external components required at all inter-
faces
s Ultralow power dissipation
s Software/hardware adjustable dc parameters and
supervision thresholds
Solid-State Ring Relay
s Low impulse noise
s Current-limited switches/thermal protection
Description
The L9312 electronic line interface and line access
circuit (LILAC) provides all the functions that are nec-
essary to interface a codec to the tip and ring of a
subscriber loop, integrating the battery feed and ring-
ing access relay in one low-power, low-cost package.
The L9312 requires a 5 V and battery supply to oper-
ate. Included is an automatic battery switch. The
battery feed offers forward battery and on-hook
transmission. It also has a low-power scan and a dis-
connect mode.
In all operating states, this IC is designed for minimal
power dissipation. This device is designed to mini-
mize the number of external components required at
all interfaces.
The dc template, current limit, and overhead voltage
and loop supervision threshold are programmable via
an applied voltage source. The voltage source may
be an external programmable voltage source or
derived from the VREF SLIC output.
The integrated solid-state switch offers power ringing
access. Impulse noise is minimized, thus eliminating
the need for external zero-cross switching circuitry.
Applications
s Pair Gain
s Digital Loop Carrier (DLC)
s Central Office (CO)
s Fiber-in-the-Loop (FITL)