AM79C2031JC AMD (ADVANCED MICRO DEVICES), AM79C2031JC Datasheet - Page 13

• Manufacturer Part Number: AM79C2031JC
• Manufacturer: AMD (ADVANCED MICRO DEVICES)

Specifications of AM79C2031JC

• Lead Free Status / RoHS Status: Supplier Unconfirmed

ASLIC/ASLAC DEVICES FUNCTIONAL DESCRIPTION
The ASLIC/ASLAC devices chipset integrates all
functions of the subscriber line. The chipset comprises
an ASLIC device and an ASLAC device. The set
provides two basic functions: 1) the ASLIC device, a
high-voltage, bipolar device that drives the subscriber
line, maintains longitudinal balance, and senses line
conditions; and 2) the ASLAC device, a low-voltage
CMOS device that combines CODEC, DC Feed control,
and line supervision. A complete schematic of a linecard
using the ASLIC/ASLAC devices chipset is shown in the
Figure 7.
The ASLIC device uses reliable, bipolar technology to
provide the power necessary to drive a wide variety of
subscriber lines. It can be programmed by the ASLAC
device to operate in eight different states that control
Power Consumption and Signaling states. This enables
full control over the subscriber loop. The ASLIC device
is customized to be used exclusively with the ASLAC
device, providing a two-chip universal line interface. The
ASLIC device requires only a +5 V power supply and a
negative battery supply for its operation.
The ASLIC device implements a linear loop current
feeding method with the enhancement of thermal
management to limit the amount of power dissipated
on the ASLIC device by dissipating excess power in
an external resistor.
The ASLAC device is a high-performance, CMOS
CODEC/filter device with additional digital filters and
circuits that allow software control of transmission,
DC Feed, and supervision.
Advanced CMOS technology makes the ASLAC
device an economical device that has both the
functionality and the low power consumption required
by linecard designers to maximize linecard density at
minimum cost.
When used with an ASLIC device, the ASLAC device
provides a complete software-configurable solution to
linecard functions. In addition, the ASLIC/ASLAC
devices chipset provides system-level solutions for
loop supervisory functions and metering. In total, the
ASLIC/ASLAC
programmable solution that can satisfy worldwide
linecard requirements by software configuration.
All software-programmed coefficients and DC Feed
parameters are easily calculated with the AmSLAC3
software. This software is provided free of charge and
runs on an IBM-compatible PC. It allows the designer
to enter a description of system requirements, then the
software returns the necessary coefficients and the
predicted system response.
The ASLAC device uses the industry standard
microprocessor
(MPI)
devices
and
chipset
PCM
interfaces
provides
P R E L I M I N A R Y
ASLIC/ASLAC Products
to
a
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communicate with the system and for interfacing to the
64 kilobit per second voice network.
The ASLIC device interface unit inside the ASLAC device
processes information regarding line voltages, loop
currents, and battery voltage levels. These inputs allow
the ASLAC device to place several key ASLIC device
performance
supervision.
The main functions that can be observed and/or controlled
through the ASLAC device control interface are:
To accomplish these functions, the ASLAC device
collects the following information from the ASLIC
device and the Central Office system:
The outputs supplied by the ASLAC device are then:
The ASLAC device performs the CODEC and filter
functions associated with the four-wire section of the
subscriber line circuitry in a digital switch. These
functions involve converting an analog voice signal into
digital PCM samples and converting digital PCM
samples
conversion, digital filters are used to band-limit the
voice signals.
The user-programmable filters set the receive and
transmit gain, perform the transhybrid balancing
function, permit adjustment of the two-wire termination
impedance,
adjustment (equalization) of the receive and transmit
paths. Adaptive transhybrid balancing is also included.
DC Feed characteristics
Ground-key detection
Off-hook detection
Metering signal
Longitudinal operating point
Subscriber line voltage and currents
Ring trip
Abrupt and smooth battery polarity reversal
The sum and difference of the currents in each loop
leg, ISUM, and IDIF
Currents proportional to the:
— voltage across the loop (IAB)
— battery voltage (IBAT)
— ringing current in the loop (IRTA – IRTB)
A current proportional to the desired DC loop cur-
rent (IDC)
A voltage proportional to the desired longitudinal off-
set voltage (VLBIAS)
A 12/16 kHz metering signal (appears on VM for
12/16 kHz teletax)
back
and
parameters
into
provide
an analog
under
frequency
signal. During
programmable
response
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