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
■ 5 V and battery operation
■ Optional automatic battery switch
■ Four operational modes
■ Appropriate for 58 dB longitudinal balance applications
■ Minimal external components required at all interfaces
■ Ultralow power dissipation
■ Software/hardware adjustable dc parameters and supervision thresholds

Solid-State Ring Relay
■ Low impulse noise
■ Current-limited switches/thermal protection

Applications
■ Pair Gain
■ Digital Loop Carrier (DLC)
■ Central Office (CO)
■ Fiber-in-the-Loop (FITL)