CX24128

Set-top Box Solutions Satellite 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. Distinguishing Features • Dual stream RF-to-baseband satellite receiver PLL Dividers, Phase Detector and Charge Pump Variable Low AGC Pass Filter Amplifier VCO VCA RF INPUT A 90 0 I Channel Output A • 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 Q Channel Output A Variable Low AGC Amplifier Pass Filter VCA RF INPUT B VCO Reference Oscillator PLL Dividers, Phase Detector and Charge Pump Reference to Demod Programming and Control 90 0 I Channel Output B Q Channel Output B • Small (7 mm x 7 mm) footprint • Lead-free package Part Number CX24128 Description Digital Satellite Dual Tuner RF IC CX24128 Block Diagram Set-top Box Solutions Satellite 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 HomePlugSM and HomePNA™. 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. CX24128 Features • State-of-the-art architecture that provides for up to 60 decibel (dB) isolation between two channels • RF input: 925–2175 MHz • Symbol rate: 1–45 MSps • Noise figure: 10 dB, typical • Input IP3 at minimum gain: 10 dBm, typical • Baseband filter bandwidth: 3–40 MHz • Output voltage: 0.5 Vp-p @ RL > 1 kΩ: • Operating temperature: 0–85º 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 © 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 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 special, indirect, incidental or consequential damages as a result of its use. 05-1503