The
Communications
Company
TM
SpeedREACH
TM
DPS8000/DPS8001
--
ADSL Full Rate Analog Front Ends
O V E R V I E W
According to a 1983 Bell system survey, 18,000 feet (18 kfeet) is the
loop distance reach needed to qualify over 95 percent of U.S. residents for
asymmetric digital subscriber line (ADSL) megabit dial-up services. ADSL access
equipment currently using chips that operate from 12-to-16 kfeet can only enable
service up to 60 percent of U.S. residents to be "loop qualified" for such mega-
bit dial-up services. That leaves the other 40 percent of U.S. residents outside
the reach of the telephone company's central office (CO). This performance
limitation can result in a significant loss of revenue for service providers. It
would cost millions to build more central offices to cover the remaining 40
percent of home users.
The performance chart (Figure 1, next page) shows that ADSL analog front-
end (AFE) chips delivered by other companies do not connect beyond distances
of 12-to-16 kfeet between a CO and a dial-up user's remote site. The chart also
shows that LSI Logic's SpeedREACH AFEs can deliver the best speed and dis-
tance performance, receiving and transmitting data well over 18 kfeet.
ADSL access equipment and high-speed modems using LSI Logic's
SpeedREACH DPS8000/DPS8001 AFEs could increase the megabit dial-up servic-
es loop reach to 95 percent of U.S. residents, thereby providing a significant com-
petitive speed and distance advantage to ADSL equipment providers.
F E A T U R E S
Complete DMT-based ADSL CO and CPE
AFEs with full RX and TX analog signal
paths [excluding POTS reject filter and
high-voltage line drivers/receivers]
Fully monolithic: Only two precision
resistors and decoupling capacitors
required
Support for echo-cancelled and fre-
quency-division based systems;
full analog echo path support
Compatible with ITU G.992.1 (G.dmt)
and G.992.2 (G.lite) standards
Supports up to 8 Mbit/s downstream
and 800 kbits/s upstream duplex
Support for 276 KHz upstream channel
for ISDN compatibility
14-Bit Linear 4.416 MS/s ADCs and
dual 14-Bit linear 4.416 MHz DACs
Programmable RX/TX attenuation/gain
4th-order low-pass filters for RX/TX paths,
with 5% cutoff frequency accuracy
RX path noise floor: 160 dBm/Hz
12-bit DAC to support external VCXO
Power dissipation:
675 mW for frequency-division mode
825 mW with full echo on
Integrated "wakeup" energy detector
for CO (DPS8000 only)
LSI Logic's SpeedREACH
AFEs support both full rate
ADSL and G.lite.
The
Communications
Company
TM
SpeedREACH
TM
DPS8000/DPS8001
D E S C R I P T I O N
ADSL technology meets the need for high-bandwidth communications using
existing twisted-pair copper infrastructure.
DPS8000/DPS8001 are a pair of highly integrated AFEs for CO-side and remote
terminal (RT)-side, respectively, for discrete multi-tone (DMT) ADSL. To support world-
wide compatibility, both chips support either frequency-division or echo-cancellation
systems, under either the full-rate ADSL or G.lite standard. Furthermore, operation of
ADSL over ISDN is also supported. Therefore, modems equipped with SpeedREACH
AFEs can operate on the vast majority of phone lines worldwide, enabling maximum
data rate with maximum reach between the CO and the RT sites.
To simplify the design, and reduce design and deployment costs, SpeedREACH
AFEs perform all of the functions of the receive (RX) and transmit (TX) paths for
ADSL. Excluding plain old telephone service (POTS) reject filtering and high-voltage
line drivers/receivers, the entire RX and TX functionality is fully integrated and
requires no external circuitry beyond a few precision resistors and bypass/
coupling capacitors.
A 4-wire serial port provides a simple DSP interface. The serial port is used
to modify internal register values, which in turn control attenuation/gain settings,
filter bandwidths and the power down of individual blocks. The chips are
powered off a +5 V supply while all digital I/Os run off a +3.3 V supply. The
DPS8000/DPS8001 are available in 128-pin LQFP plastic packages. The operat-
ing temperature range is between -40 C and +85 C.
For more information please call:
LSI Logic Corporation
North American Headquarters
Milpitas, CA
Tel: 800 574 4286
LSI Logic Europe Ltd.
European Headquarters
United Kingdom
Tel: 44 1344 426544
Fax: 44 1344 481039
LSI Logic KK Headquarters
Tokyo, Japan
Tel: 81 3 5463 7165
Fax: 81 3 5463 7820
LSI Logic web site
www.lsilogic.com
LSI Logic logo design, is a registered trademark
and SpeedREACH is a trademark of LSI Logic
Corporation. All other brand and product names
may be trademarks of their respective companies.
LSI Logic Corporation reserves the right to make
changes to any products and services herein at any
time without notice. LSI Logic does not assume any
responsibility or liability arising out of the applica-
tion or use of any product or service described
herein, except as expressly agreed to in writing by
LSI Logic; nor does the purchase, lease, or use of a
product or service from LSI Logic convey a license
under any patent rights, copyrights, trademark
rights, or any other of the intellectual property
rights of LSI Logic or of third parties.
Copyright 2001 by LSI Logic Corporation.
All rights reserved.
Order No. R20029
101.1k.JG.TP - Printed in USA
Figure 1. The two critical AFE
performance parameters are
linearity (in bits) and noise
floor (in dBm/Hz).
A
chievable Data Rate (Mb
p
s)
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