BOARDCOM BCM3348

BCM3416
®
ADVANCED DIGITAL CABLE TUNER
SUMMARY OF BENEFITS
FEATURES
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• Narrowband first IF eliminates processing of unnecessary
Supports 64 and 256 QAM
Input frequency range of 50 MHz through 860 MHz *
IF output range of 36 MHz through 44 MHz
High linearity across entire frequency range
channels
• DOCSIS and EuroDOCSIS 1.0/1.1/2.0 compliant
• Minimal in-house RF expertise required
• Superior alternative to can tuners
Differential signals for high noise immunity
• High quality and reliability (no hand tweaking)
• Enables lower profile and smaller designs
• Simplified manufacturing flow
• Lower BOM cost
• Applications
• Cable modems
• Cable set-top boxes
Eliminates need for image reject mixer
Highly integrated and cost-effective
• Minimal BOM with reference designs available
• IF AGC and frequency synthesizers included
• Standard logic CMOS with single 3.3V supply
• 48-pin TQFP
* = For use only in applications where the input frequency to the
diplexer is less than 1000 MHz.
Tuner Application Example (Cable Modem)
SDRAM
NB
SAW
Diplex
Filter
50-860 MHz
FLASH
SAW
BCM3401
BCM3416
LNA
CMOS Tuner
BCM3348
Single-Chip
DOCSIS/EuroDOCSIS
2.0 Cable Modem
50-860 MHz
5-65 MHz
OVERVIEW
TQFP-48
IF AGC
1270-2080 MHz
PLL 1
1176 MHz
PLL 2
10 MHz ref.
Overview
Technical Brief
The BCM3416 is a highly integrated silicon tuner. The BCM3401,
containing an LNA and the RF AGC, is the companion part to the
BCM3416. This two-chip solution supports both 64-QAM and
256-QAM digital cable modem applications.
The signal is passed from the BCM3401 to the up conversion mixer. The
up conversion mixer translates the input up to a fixed first IF of
1220 MHz. The narrowband first IF eliminates processing of
unnecessary channels.
The BCM3416 and BCM3401 are specifically designed to work with
Broadcom’s industry-leading BCM3345, BCM3360, BCM3348, and
BCM3250 single-chip cable modems, and form an attractive alternative
to traditional can tuners in any cable modem design.
The down conversion mixer brings the signal down to the output IF of
43.75 MHz (or 36.125 MHz for PAL). The IF amplifier buffers the
differential output signal that can directly drive an external SAW filter,
where the final channel selection filtering occurs.
The BCM3416 supports an IF output frequency range of 36 MHz
through 44 MHz and specifically supports the 36.125 MHz and
43.75 MHz center frequencies for the PAL and NTSC standards. Also,
the BCM3416 and BCM3401 chipsets are DOCSIS and EuroDOCSISbased.
The IF AGC amplifies the signal returned from the SAW filter over a
30-dB range and buffers the differential output signal. The signal is then
appropriately biased to the input of the BCM3345, BCM3360,
BCM3348, and BCM3250.
A two-wire MBus-compatible serial bus controls the chip.
Great care was taken to develop the proven reference designs, which also
minimize the external components required. This system’s expertise
allows our customers to design with confidence even if they have
minimal in-house RF expertise, while lowering their overall BOM cost
versus the traditional can tuners.
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
© 2003 by BROADCOM CORPORATION. All rights reserved.
3416-PB04-R
09/04/03
Phone: 949-450-8700
Fax: 949-450-8710
E-mail: [email protected]
Web: www.broadcom.com