BCM3037 Datasheet, PDF (2/2 Pages) Broadcom Corporation. – BCM3037 QAMLINK-R UNIVERSAL BURST MODULATOR

OVERVIEW
TX_SOC
TX_ENAB
TX_CLK
TX_DATA
TX_CLAV
Randomizer
Burst
FIFO
FEC
Interface
Preamble
Prepend
QPSK/QAM
Symbol
Mapper
RS
Encoder
PLL
Timing and Control
Nyquist F ilter Interpolation
(α= 0.25/0.50)
Filters
cos ϖn ^X
Transmitter
Pre-Equalizer
DDFS
+
sin ϖn
X
x
sin x
2
DAC
A_IF±
IBIAS_DAC
Nyquist F ilter Interpolation
(α= 0.25/0.50)
Filters
SBUS
JTAG
5
TM [4:0]
Test ¹¹
TP [10:0]
MCLK XTALO TX_NOW TX_OEN RST
12C ADDR0 ADDR1 SDA SCL
SPI
SS MISO MOSI SCK
TCK TMS TDI TDO
The BCM3037 provides a complete π/4 DQPSK, QPSK and 16-QAM
Upstream Burst Modulator and FEC encoder integrated on a single chip.
A burst FIFO buffer provides input data rate decoupling. The FEC
encoder consists of a programmable randomizer and a programmable RS
encoder. There is also a programmable preamble prepend,
programmable symbol mapper, and a programmable transmitter pre-
equalizer. The modulator consists of dual square-root raised cosine
filters with programmable excess bandwidth, α=0.25 or α=0.50,
interpolation filters, and a digital upconverter which translates the
shaped pulse to a digitally tunable IF center frequency. An integrated 10-
bit DAC then converts this signal to an analog waveform with
programmable attenuation.
The BCM3037 accepts a serial data stream and transmit control inputs.
The output consists of an analog modulated and filtered data burst
containing data at variable symbol rates and three modulation formats,
which are π/4 DQPSK, QPSK and 16-QAM. Modulation can include
differential or non-differential encoding. The modulated burst consists of
a power up, ramp up, preamble, data, FEC, ramp down, guard time and
power down in each burst. The output of the BCM3037 can then be sent
to a power amplifier. There are standard DAVIC A0 and ATM UTOPIA
serial input interfaces provided. There is also a generic byte-based
interface. Alternatively, the BCM3037 can be configured to provide a
data bit clock for synchronizing data. Control information is input
through either an I²C-compatible or SPI-compatible serial interface.
The BCM3037 can be used as a stand-alone chip or with one of
Broadcom’s QAMLink Receivers/Transceivers. The 10-bit D/A
converter in the BCM3037 eliminates fine tuning of external
components during high-volume production, which significantly
decreases the overall system manufacturing costs. A frequency agile
output of [5-65 MHz] that the BCM3037 can generate compensates for
severe ingress and effectively combats harsh upstream environments
found in coaxial cable applications. The BCM3037 supports all of the
cable transmission standards, including SCTE, IEEE802.14, DOCSIS/
EuroDOCSIS, DVB, and DAVIC, making it an optimal upstream
solution for worldwide coaxial cable applications.
Broadcom^®, the pulse logo, and Connecting everything^® are trademarks of Broadcom Corporation and/
or its subsidiaries in the United States and certain other countries. All other trademarks mentioned are the
property of their respective owners.
®
BROADCOM CORPORATION
16215 Alton Parkway, P.O. Box 57013
Irvine, California 92619-7013
© 2004 by BROADCOM CORPORATION. All rights reserved.
3037-PB06-R
07/08/04
Phone: [phone]
Fax: [phone]
E-mail: [e-mail]
Web: www.broadcom.com