AM79Q4457 Datasheet, PDF (1/44 Pages) List of Unclassifed Manufacturers – Quad Subscriber Line Audio Processing Circuit-Non-Programmable (QSLAC-NP) Devices

Am79Q4457/5457
Quad Subscriber Line Audio Processing Circuit-
Non-Programmable (QSLAC™-NP) Devices
DISTINCTIVE CHARACTERISTICS
n Performs the function of four Codec/Filters
n A-law or µ-law coding
n Single PCM port
— Up to 4.096 MHz operation (64 channels)
n Hardware programmable (via external
components)
— Transhybrid balance impedance
— Transmit and receive gains
n Additional Am79Q4457 device capabilities
(per channel, set external)
— Three selectable transmit gains
— Three selectable receive gains
— Two selectable balance networks
— Simple serial control interface
n Separate PCM and Master clocks
n 1.536 MHz, 1.544 MHz, 2.048 MHz, or 4.096 MHz
master clock options
— Internal timing automatically adjusted based on
MCLK and frame sync signal
n Low power 5.0 V CMOS technology
n 5.0 V only operation
GENERAL DESCRIPTION
The Am79Q4457/5457 Quad Subscriber Line Audio
Processing Circuit-Non-Programmable (QSLAC-NP)
device integrates the key functions of analog linecards
into a high-performance, four-channel Codec/Filter
device. The QSLAC-NP devices are based on the
proven design of the reliable Am79C02/03/031(A)
Dual Subscriber Line Audio-Processing Circuit
(DSLAC^™) devices, and the Am79C202 Advanced
Subscriber Line Audio-Processing Circuit (ASLAC^™)
device. The advanced architecture of the QSLAC-NP
devices implements four independent channels in a
single integrated circuit, providing a cost-effective
solution for the audio-processing function of Plain Old
Telephone Service (POTS) linecards.
The Am79Q4457/5457 QSLAC-NP device provides
four industry-standard Codec/Filter devices in a single
integrated circuit. The Am79Q4457/5457 device
provides a transmit and receive frame synchronization
input per channel. A-law or µ-law compression is
selected via a device pin.
In addition, the Am79Q4457 device provides the ability
to select one of three independent gain settings (both
transmit and receive) and one of two balance networks
on a per-channel basis. The transmit and receive gain
levels are set once for the device via external
components. Gain level selection and the balance
network selection is achieved through an integrated
serial shift register and latch per channel.
The Am79Q5457 device provides four industry-
standard Codec/Filter devices in a 32-pin PLCC or 44-
pin TQFP package. The Am79Q4457 device provides
four industry-standard Codec/Filter devices and
selectable gain and balance functions in a 44-pin PLCC
or 44-pin TQFP package.
Advanced submicron CMOS technology enables the
Am79Q4457/5457 QSLAC-NP device to have both
the functionality and the low power consumption
required in linecard designs, maximizing linecard
density at a minimum cost. When used with four
Legerity SLICs, a QSLAC-NP device provides a
complete solution to the BORSCHT function of a
POTS linecard.
Although the name and logo have changed, the data contained herein
remains the same as the most recent AMD revision of this document.
Publication# 20031 Rev: D Amendment: /0
Issue Date: January 2000