BCM3520
®
ATSC/NTSC/QAM DIGITAL CABLE READY DTV RECEIVER
FEATURES
•
Integrated VSB/QAM QAMLink
®
receiver
12-bit A/D converter with internal AGC amplifier
Full equalizer architecture spans up to –35 to 49 µs delays
Direct IF sampled architecture reduces system cost
Single IF signal path for QAM/VSB/NTSC to reduce system
costs
-
ITU-T J.83 Annex A/B/C FEC modes
-
MPEG-2 transport output (serial/parallel)
-
All-digital clock and carrier recovery
-
Integrated PLLs to minimize external components
-
All acquisition times typically less than 50 ms
•
QPSK out-of-band receiver
-
100–200-MHz receiver LO with input AGC and 6-bit A/D
-
Variable symbol rate QPSK receiver
-
Digital demodulator, Nyquist filters, tracking loops, and
four-tap adaptive equalizer
-
DVS-167 (Davic™)/DVS-178 (DigiCipherII™) FEC decoder
•
NTSC/PAL IF Demodulator
-
Adjacent channel rejection filters
-
Programmable digital audio trap filter
-
Programmable group delay compensation filter
-
Analog Composite Video Baseband Signal (CVBS) output
-
FM demod output supports internal BTSC stereo decoder,
external BTSC stereo decoder (baseband or IF input), or
external Zweiton M decoder
•
Integrated acquisition controller
-
-
-
-
SUMMARY OF BENEFITS
•
Complete DTV single chip receiver solution
•
FCC VSB and Digital Cable Ready
•
Superior performance under both static and dynamic multi-
path channel conditions
•
Integrated NTSC demodulator
•
BTSC decoder on chip
•
•
•
•
•
Direct interface to CMOS and discrete DTV tuners
Reduces system costs through direct IF sampling
Single IF path for QAM/VSB/NTSC simplifies board design
Smart antenna support
Automatic NTSC co-channel interference and RFI rejection
filters
•
Integrated de-interleaver RAM for VSB FEC, and QAM for
modes up to J=4 reduces system costs
•
Analog stereo, mono, or SAP outputs
•
I
2
S or baseband multiplexed audio output
•
On-chip stereo audio DACs
•
BSC master to control peripherals
•
EIA/CEA-909 antenna interface
•
144-pin LQFP package
Plug and Play DTV System Solution
Cable
ATSC
BCM3431
LNA
BCM3418
Tuner
MPEG Transport Serial/Parallel
Composite Video
BCM3520
Out-of-Band
VSB/QAM
OOB/CableCard™
Audio: I2S, L/R, Multiplex Baseband, IF Audio
Out-of-band Transport
EIA/CEA-909
Smart Antenna Interface
OVERVIEW
BSC/SPI Host Interface
BSC/SPI Slave
Interface
HAB
Acquisition
Processor
Internal Bus
To All Blocks
Master
PLL
54-MHz 3
rd
Overtone Crystal
Interrupt
In-Band Tuner
In-Band AGC
In-Band AFT
16-1024 QAM
Advanced Receiver
OOB Tuner
OOB AGC
OOB VCO
OOB AFE
PGA
6-Bit A/D
AGC Control
VCO
ITU-T J.83
Annexes A/B/C FEC
In-Band AFE
PGA
12-Bit A/D
AGC Control
ATSC 8/16 VSB
Advanced Receiver
ATSC FEC
Output
Interface
MPEG Transport
10-Bit D/A
NTSC IF
DEMODULATOR
10-Bit D/A
Composite NTSC
IF Audio
I
2
S
OOB QPSK
Receiver
BTSC
Decoder
HiFi DAC
L/R Audio or Multiplexed
Baseband Audio
DVS-167 FEC
DVS-178 FEC
BSC Master
Interface
GPIO/GPO
Interface
EIA/CEA-909
Interface
OOB Output
Interface
OOB Transport for
CableCard/POD
BCM3520
JTAG
Interface
Tuner/Peripheral
Control
GPIO
GPO
Antenna
Control
JTAG
Controller
BCM3520 Block Diagram
The BCM3520 is a ATSC/NTSC/QAM Digital Cable Ready DTV
receiver that contains a digital receiver that is compatible with both
North American digital cable television and digital terrestrial broadcast
television standards. This receiver is capable of receiving all standard-
definition and high-definition digital formats (SDTV/HDTV). It also
contains an IF demodulator compatible with the NTSC video standard.
The output of the IF demodulator can be directed to an external BTSC or
Zweiton M decoder, or can be sent to an on-chip audio decoder. The on-
chip audio decoder is fully compliant with the BTSC audio standard. An
out-of-band QPSK receiver is also contained to meet the needs of the
CableCard specification.
The BCM3520’s digital receiver and NTSC demodulator accepts an
analog signal centered at the standard television IF frequencies, and
amplifies and digitizes this signal with an integrated programmable gain
amplifier and 12-bit A/D converter. The output of the A/D is sent to the
receiver and demodulator. The digital receiver consists of a QAM
demodulator and a VSB demodulator. Each demodulator contains
adaptive filters that remove multi-path propagation effects, NTSC co-
channel interference, and RFI interference. The output of the VSB
demodulator goes to an ATSC A/53 coding forward error corrector
(FEC), with integrated trellis and Reed-Solomon decoder. The output of
the QAM demodulator goes to an ITU-T J.83 Annex A/B/C coding FEC.
The output of either QAM or VSB FEC is delivered in either parallel or
serial MPEG-2 transport format. The NTSC demodulator filters and
demodulates the analog NTSC and FM audio signals and delivers a
composite output via an on-chip 10-bit DAC. An IF modulated audio
output is also provided via a second on-chip 10-bit DAC. An on-chip
BTSC decoder handles the decoding of the base-band multiplexed audio
from the IF demod, providing an stereo left/right, mono, or SAP output
via a pair of high precision HiFiDACs.
All gain, clock, and carrier, acquisition, and tracking loops are integrated
on-chip as are the necessary phase-locked loops, referenced to a single
external crystal.
Chip configuration, channel acquisition, and performance monitoring
functions are conducted by the on-chip acquisition processor using
Broadcom-provided software.
Broadcom
®
, the pulse logo,
QAMLink
®
, Connecting everything
®
, and the Connecting everything logo
are among the trademarks of Broadcom Corporation and/or its affiliates in the United States, certain other
countries and/or the EU. Any other trademarks or trade names mentioned are the property of their
respective owners.
®
BROADCOM CORPORATION
16215 Alton Parkway, P.O. Box 57013
Irvine, California 92619-7013
© 2006 by BROADCOM CORPORATION. All rights reserved.
3520-PB05-R
10/23/06
Phone: 949-450-8700
Fax: 949-450-8710
E-mail: info@broadcom.com
Web: www.broadcom.com
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