BOARDCOM BCM3431

BCM3418
PRODUCT
Brief
®
BCM3418
CMOS
B C M 3 4 1 8
VoIP
F E AT U R E S
CABLE
S U M M A R Y
• Supports 64 - 256 QAM
• Input Noise Figure 12 dB
• IP3 = 15 dBm (two tone)
• SNR 40 dB
• CTB, CSO, Xmod all > 50 dB
• PLL Step Size 100 KHz
• IF AGC 30 dB Range
• 48-Pin TQFP Package
• .5W @ 3.3V
O F
TUNER
B E N E F I T S
• The BCM3418 supports 64- and 256-QAM digital cable
applications
• Low cost
• Complete TV tuner-on-a-chip – requires no external high
frequency tuned circuits
• Simplifies board layout
• Single 3.3V supply
• Eliminates microphonics
• Differential signals for noise immunity
• Surface-mount package simplifies manufacturing
• Applications
• Cable Modems
• VoIP
BCM3418 Tuner Application Example (Cable Modem)
Diplex
Filter
54-860 MHz
Discrete
BCM3418
LNA
CMOS Tuner
PA
LPF
5-65 MHz
SAW
BCM3300
QAM Rx
QPSK/QAM Tx
MCNS 1.1 MAC
SRAM
SDRAM
FLASH
BCM3310
MIPS CPU
PCI I/F
Control
PCI BUS
B C M 3 4 1 8
O V E R V I E W
IF AGC
PLL
The BCM3418 is a complete QAM Digital Cable Tuner-on-achip that supports both 64- and 256-QAM applications. The
BCM3418 utilizes a highly integrated version of the single
conversion architecture. The input signal is split into three bands,
each with a variable bandpass filter and mixer, controlled by a
two-wire serial bus that is MBus compatible. The IF amplifier
buffers the differential output signal that can directly drive an
external SAW filter, where the final channel selection filtering
occurs. The IF AGC amplifies the signal returned from the SAW
filter over a 30 dB range and buffers the differential output
signal.
®
Broadcom®, the Pulse logo, QAMLink®, and Connecting everything are trademarks of
Broadcom Corporation and/or its subsidiaries in the United States and certain other countries.
All other trademarks are the property of their respective owners.
®
BROADCOM CORPORATION
16215 Alton Parkway, P.O. Box 57013
Irvine, California 92619-7013
© 2003 by BROADCOM CORPORATION. All rights reserved.
3418-PB03-R 06.25.03
Phone: 949-450-8700
FAX: 949-450-8710
Email: info@broadcom.com
Web: www.broadcom.com