BCM3034
UNIVERSAL ADVANCED DOWNSTREAM MODULATOR
Integrated QAMLink Advanced downstream modulator
Supports 4, 16, 32, 64, 128, 256, 512 and 1024 QAM
Variable symbol rates up to 10 Mbaud
Programmable 80-tap dual square-root Nyquist filters
Programmable complex 24-tap T/2 pre-distortion filter
Digital interpolation filters
Quadrature direct digital frequency synthesizer and upconverter
X/sinX filter for DAC distortion compensation
Fully integrated ITU-T J.83 Annex A (DVB/DAVIC/EuroDOCSIS /
IEEE802.14), Annex B (DigiCipher II/SCTE/DOCSIS/IEEE 802.14
and Annex C (Japan) FEC encoder
All codes extended to support 512/1024-QAM
On chip 64K static RAM for interleaving
Integrated 10-bit digital-to-analog converter
Integrated additional burst modulator for power management of CPE
equipment
Optional 12- or 14-bit digital IF output for external DAC
I
2
C or SPI-compatible microcontroller interface
JTAG test interface
128-pin PQFP package
Operates over industrial temperature range (-40 to +85 degrees C)
Presents a high-performance, integrated solution for modulators in
digital cable-TV head-end, Cable Modem Termination Systems
(CMTS), digital microwave radio, SMATV and MMDS applications.
An integrated solution that reduces board space and costs with:
On-chip 64K static RAM to eliminate external RAM
Integrated 10-bit DAC with power control
Additional burst modulator for out-of-band signaling
Small footprint to enable high-density equipment
Improves bandwidth efficiency through 512/1024-QAM modulation.
Enables advanced digital services over narrow RF channels.
Supports North American, European and Asian modulator standards
enabling a single design for worldwide application.
Programmable analog IF outputs up to 100 MHz simplifies image
rejection filters.
Programmable high-granularity digital output options remove the
need for SAW filters in final RF stage while providing designers
multiple options in DAC selection.
Advanced functions deploy in harsh environments.
Distributed CMTS in Hybrid Fiber Coaxial Fiber Node
F E A T U R E S
S U M M A R Y O F B E N E F I T S
5-65 MHzUpstream
BCM3138
BCM3138
Routing/
Classification
Engine
Ethernet
System
CPU
Memory
PCI Bus
BCM3212
CMTS MAC
Downstream
SDRAM
(PHS,
output
queues)
LPF
PA
WAN
44 MHz IF
BCM3138
Dual Adv. PHY
Receiver
BCM3034
Advanced QAM
Modulator
Cable Modem Termination System (CMTS) Block Diagram
O V E R V I E W
Phone: 949-450-8700
Fax: 949-450-8710
E-mail: info@broadcom.com
Web: www.broadcom.com
BROADCOM CORPORATION
16215 Alton Parkway, P.O. Box 57013
Irvine, California 92619-7013
2004 by BROADCOM CORPORATION. All rights reserved.
3034-PB04-R
07/01/04
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.
The BCM3034 QAMLink Universal Modulator is a highly integrated
solution that significantly decreases the board space and cost of
modulators in digital cable-TV head-ends, digital cable modem head-
ends, digital microwave radio, SMATV and MMDS applications. The
BCM3034 features an advanced downstream QAM modulator that
includes an extended ITU-T J.83 Annex A/B/C FEC encoder, an all-
digital QAM modulator supporting up to 1024-QAM, and an integrated
10-bit D/A converter with power control. Additionally, the BCM3034
includes a second modulator that can be used for out-of-band signaling
or CPE power control.
The advanced downstream QAM modulator supports symbol rates up to
10 MBaud and symbol constellations from QPSK up to 1024-QAM,
enabling up to 100 Mbps operation. The modulator accepts either a serial
or parallel data stream, optionally recovers the data timing and encodes
the data with one of the supported coding standards. The resulting
stream of QAM symbols then enters the modulator where the data pulses
are shaped by the dual programmable linear phase square-root Nyquist
filters. Built-in coefficients are provided for these filters for industry-
standard excess bandwidth factors (alpha = 12%, 15% or 18%). The
filtered data is then passed through a 24-tap complex T/2-spaced
predistortion filter. This filter allows the user to compensate for non-
idealities, such as slope distortion, introduced elsewhere in the RF
portion of a design. Interpolation filters then upsample the signal to the
output sample rate while providing additional signal filtering. A
quadrature direct digital frequency synthesizer and I/Q modulator allows
the QAM spectrum to be mixed to a precise output center frequency. The
spectrum can then be predistorted by the integrated X/sinX filter to
compensate for DAC distortion. The final signal can be output to the
integrated 10-bit, 200-MS/s D/A converter, which includes differential
analog outputs and a gain stage that can set the output power in 0.4 dB
steps. Alternatively, a selectable 12- or 14-bit digital IF output can drive
an external D/A converter with sufficient linearity to enable final RF
sections that do not require the use of SAW filters to meet industry-
standard RF output templates.
The BCM3034 is a flexible, cost-effective worldwide solution. Because
the chip accepts variable data rates and supports multiple digital
transmission standards, manufacturers only need to develop one
modulator for worldwide usage. The integrated feature set in the
BCM3034 significantly reduces the board space in modulators, giving
manufactures a chip solution that is both cost-effective and easy to use.
Interpolation
Filter
QDDFS
D/A
PLL / Clock Generation
Interpolation
Filter
Nyquist
= .12-.18
Output Clock PLL
A_IF +/-
PS_VALID
PS_IN[7:0]
8
D_IF[13:0]
DAC_CLK
PS_SYNC
24-tap
Pre-
Filter
distortion
Source Clock Generator
OB_DIN
PS_CLK
SCALE
X
sin X
Extended
ITU-T J.83
Annex A/B/C
Encoder
Programmable
Nyquist
= .12-.18
Programmable
Programmable
RS
FEC
Encoder
D/A
OB_IF +/-
4/16/32 QAM
Pwr. Mgmt.
Modulator
Burst
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