L9500A Introduction
The Agere Systems Inc. L9500A 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 (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. This device is optimized to interface to data over cable service interface specification (DOCSIS) compliant cable modem gateway, multi-media adaptor, and residential gateway products, such as the Broadcom® BCM3351, BCM3352, BCM6352, and BCM1101 and equivalent products.

Features
■ Differential ringing and codec interface
■ Onboard ringing generation
■ Three ringing input options:
    — Sine wave
    — PWM
    — Logic level square wave
■ Flexible VCC options:
    — 5 V or 3.3 V VCC
    — No –5 V required
■ Battery switch to minimize off-hook power
■ Eight operating states:
    — Scan mode for minimal power dissipation
    — Forward and reverse battery active
    — On-hook transmission states
    — Ground start
    — Ring mode
    — Disconnect mode
■ Ultralow on-hook power:
    — 27 mW scan mode
    — 38 mW active mode
■ Loop start, ring trip, and ground start detection
■ Software-controllable dual current limit option
■ 28-pin PLCC package
■ 48-pin MLCC package

Applications
■ Interface to Broadcom:
    — BCM3351 Cable Modem
    — BCM3352 Cable Modem
    — BCM6352 Integrated Multi-Media Adaptor
    — BCM1101 Residential Gateway
■ Cable Modem
■ Voice over Internet Protocol (VoIP)
■ Voice over DSL
■ Remote Subscriber Units
■ Broadband Wireless
■ Short Loop Access