+14dBm to +20dBm LO Buffers/Splitters with ±1dB Variation

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The MAX9987 and MAX9988 LO buffers/splitters each integrate a passive two-way power splitter with highisolation input and output buffer amplifiers. These buffers are designed to provide the high output (+14dBm to +20dBm) necessary to drive the LO inputs of high-linearity passive mixers, while offering 40dB reverse isolation to prevent LO pulling. The MAX9987 is internally matched for the cellular/GSM bands, and the MAX9988 is matched for the DCS/PCS/UMTS bands.

The typical application circuit provides a nominal +17dBm output power with ±1dB variation over supply, temperature, and input power. With two optional resistors, the output power can be precision set from +14dBm to +20dBm. The devices offer more than 30dB output-to-output port isolation, and are offered in 5mm x 5mm 20-pin thin QFN packages with exposed paddle.
MAX9987, MAX9988: Typical Operating Circuit MAX9987, MAX9988: Typical Operating Circuit Enlarge+

Key Features

  • ±1dB Output Power Variation
  • +14dBm to +20dBm Adjustable Output Power
  • Two-Way Power Splitting
  • 40dB Reverse Isolation
  • More than 30dB Output-to-Output Isolation
  • Low Output Noise: -170dBc/Hz at +17dBm
  • 160mA Supply Current at +17dBm
  • Isolated PLL Output (+3dBm)
  • Applications/Uses

    • Base-Station Main and Diversity Channels
    • Cellular/GSM/DCS/PCS/UMTS Base Station
    • Coherent Receivers
    • ISM Wireless LAN
    • Local Multipoint Distribution Service
    • Point-to-Point Systems
    • Tx/Rx LO Drive
    • Wireless Local Loop (WLL)
    Request Reliability Report for: MAX9987 
    Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C   Material Composition  

    Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

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