a
Discrete Multitone (DMT) Coprocessor
for ADSL Chipsets
AD6439
FEATURES
Component in Analog Devices’ AD20msp918 ADSL
Chipset
Designed to ANSI T1.413 Issue 2/ETSI TR238/ITU
G.992.1 and G.992.2
Higher Performance
Improved Data Rates or Longer Reach
Suitable for CO or Residence (ATU-R and ATU-C)
Performs All DMT Functions and Operations
Trellis Coding
Echo Cancellation
Symmetric Transforms (512 Point)
Flexible Allocation of Tones Upstream/Downstream
Supports Symmetric Services (SDSL)
Increased Upstream (e.g., 1 Mbps)
Supports ADSL Over ISDN (Shifted U/S)
Strict Filters for Spectral Compatibility
128-Lead MQFP
–40؇C to +85؇C, 3.3 V Operation, 1.1 W
GENERAL DESCRIPTION
The AD6439 Discrete Multitone (DMT) Coprocessor is part of
Analog Devices ADSL solution, a series of flexible, standardsbased chipsets for creating high performance ADSL and SDSL
modems that implement a superset of standard Category 2
functionality.
A high performance alternative to the AD6436 DMT Coprocessor,
the AD6439 meets the functionality requirements of ANSI
T1.413 Category 2 (trellis coding, echo cancellation), but is
considerably more versatile. It implements both transmit and
receive paths (trellis coding/decoding, IFFT/FFT, filtering and
echo cancellation). Symmetric transforms allow flexible allocation of upstream and downstream bandwidth, including symmetric data rates. Improved digital filters exceed the requirements
of T1.413 and deliver strict spectral masks (e.g., for VDSL
compatibility).
FUNCTIONAL BLOCK DIAGRAM
TX SERIAL
AD6435
OR
AD6436
INTERFACE
FRAMER
RX SERIAL
DSP PORT
TRELLIS
IFFT
512/512PT
TX PATH
FILTERS
EC
ENCODE/
DECODE
IFFT
512/512PT
MULTIPLEXER
DIGITAL FILTER
16
DAC
AD6440
OR
AD6437
16
RX PATH
FILTERS
ADC
CONTROL LOGIC
REV. 0
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reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
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Tel: 781/329-4700
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Fax: 781/326-8703
© Analog Devices, Inc., 1999
