Set-top Box Solutions
Satellite
Distinguishing Features
Dual stream RF-to-baseband
satellite receiver
State-of-the-art architecture that
provides for up to 60 decibel (dB)
isolation between two channels
Zero-IF architecture eliminates the
need for image reject filtering
Very low phase noise for 8PSK and
DVB-S2 applications
Variable baseband filters for optimal
interference rejection
Auto-tuning machine eliminates need
for software calibration
Very low power consumption
Small (7 mm x 7 mm) footprint
Lead-free package
Part Number CX24128
Description Digital Satellite Dual Tuner RF IC
Digital Satellite Dual Tuner RF IC
CX24128
Industry's First Dual Tuner for DVR Applications
Conexant's portfolio includes a comprehensive suite of semiconductor solutions for
broadband communications, enterprise networks and the digital home. The CX24128
is Conexant's innovative dual stream direct down-conversion satellite tuner RF IC
intended for high-volume digital video, audio, and data receivers. The CX24128 offers
excellent phase noise performance and very low implementation loss, required for
advanced modulation systems such as 8PSK and DVB-S2. The CX24128 provides
bill of materials (BOM) savings over two single tuners and simplifies layout for DVR
set-top boxes (STBs).
The CX24128 has a built-in auto-tuning machine that eliminates the need for software
calibration routine and accelerates the calibration time. The on-chip fractional
synthesizers enable fine frequency step size without adversely affecting lock time.
The CX24128 requires a single 3.3 V power supply and has an improved power
supply rejection ratio (PSRR) that reduces the need for power supply conditioning
components required for proper operation. The CX24128 does not require a Balun,
thus reducing external BOM cost. Its highly integrated design saves valuable board
space and simplifies RF layout.
CX24128 Block Diagram
VCO
VCA
VCA
VCO
Variable Low
Pass Filter
PLL Dividers, Phase
Detector and Charge Pump
PLL Dividers, Phase
Detector and Charge Pump
Programming
and Control
Reference
to Demod
Variable Low
Pass Filter
AGC
Amplifier
AGC
Amplifier
Reference
Oscillator
90
0
RF INPUT
A
RF INPUT
B
I Channel
Output A
Q Channel
Output A
Q Channel
Output B
90
0
I Channel
Output B
2005, Conexant Systems, Inc. All Rights Reserved. Conexant and the Conexant
logo are registered trademarks of Conexant Systems, Inc. All other trademarks
are owned by their respective owners. Although Conexant strives for accuracy
in all its publications, this material may contain errors or omissions and is
subject to change without notice.
THIS MATERIAL IS PROVIDED AS IS AND WITHOUT
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING MERCHANTABILITY, FITNESS FOR A
PARTICULAR PURPOSE AND NON-INFRINGEMENT.
Conexant shall not be liable for any
special, indirect, incidental or consequential damages as a result of its use.
05-1503
Set-top Box Solutions
Satellite
CX24128 Features
State-of-the-art architecture that provides for up
to 60 decibel (dB) isolation between two channels
RF input: 9252175 MHz
Symbol rate: 145 MSps
Noise figure: 10 dB, typical
Input IP3 at minimum gain: 10 dBm, typical
Baseband filter bandwidth: 340 MHz
Output voltage: 0.5 Vp-p @ RL > 1 k:
Operating temperature: 085 C
Package type: 48-pin, Pb- free, QFN
Applications
Advanced modulation set-top boxes
DSS/DVB set-top boxes
Digital VCR (DVR)
Commercial digital video, audio and data receivers
Conexant Product Portfolio
The company's broad portfolio of semiconductor products also
includes client-side DSL and cable modem solutions, home
network processors, broadcast video encoders and decoders,
digital set-top box components and systems solutions, and
dial-up modems. In addition to its IEEE 802.11a/b/g-compliant
WLAN chipsets, software, and reference designs, Conexant
offers a suite of networking components that includes solutions
for applications based on HomePlug
SM
and HomePNATM.
Additional products include a complete line of asymmetric and
symmetric DSL central office solutions, which are used by service
providers worldwide to deliver broadband data, voice, and video
over copper telephone lines.
www.conexant.com
General Information:
U.S. and Canada: (888) 855-4562
International: (732) 345-7500
Headquarters
4000 MacArthur Blvd.
Newport Beach, CA 92660
Order# 102375C
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