Analog Devices MAX2121B Product Info

• Monolithic Receiver Saves Cost and Space
  • Integrated VCO with Low Phase Noise: -97dBc/Hz at 10kHz
  • Integrated 14-Bit Fractional-N Synthesizer
  • Address Pin Allows for Multi-Tuner Applications
• Low Power Reduces Cost
  • 495mW Power Dissipation
  • 10mW Standby Mode
• High Dynamic Range Eliminates Need for External LNA and/or Attenuators
  • -75dBm to 0dBm Input Power
  • 8dB Noise Figure
• Integrated LP Filters Simplify Design
  • Programmable Bandwidth from 40MHz to 124MHz
• Differential I/Q Interface Minimizes EMI
  • 1V_P-P Full-Scale Outputs
• Serial Interface and Small Package Reduce Size
  • 5mm x 5mm, 28-Pin TQFN Package
  • I²C 2-Wire Serial Interface

The MAX2121B low-cost, direct-conversion tuner IC is designed for satellite set-top and VSAT applications.

The device directly converts the satellite signals from the LNB to baseband using a broadband I/Q downconverter. The operating frequency range extends from 925MHz to 2250MHz.

The device includes an LNA and an RF variable-gain amplifier, I and Q downconverting mixers, and digitally controlled baseband filters (40MHz to 124MHz) and variable-gain amplifiers. Together, the RF and baseband variable-gain amplifiers provide more than 80dB of gain control range.

The device includes fully monolithic VCOs, as well as a complete fractional-N frequency synthesizer. Additionally, an on-chip crystal oscillator is provided along with a buffered output for driving additional tuners and demodulators. Synthesizer programming and device configuration are accomplished with a 2-wire serial interface. The IC features a VCO autoselect (VAS) function that automatically selects the proper VCO. For multituner applications, the device can be configured to have one of two 2-wire interface addresses. A low-power standby mode is available whereupon the signal path is shut down while leaving the reference oscillator, digital interface, and buffer circuits active, providing a method to reduce power in single and multituner applications.

The device is the most advanced broadband/VSAT DBS tuner available. The low noise figure eliminates the need for an external LNA. A small number of passive components are needed to form a complete broadband satellite tuner DVB-S2 RF front-end solution. The tuner is available in a very small, 5mm x 5mm, 28-pin TQFN package.

Applications

• DBS Tuner
• Navigation Systems
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