+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)

    See parametric specs for VCO Buffers/Splitters (7)

    Part NumberLO Driver OutputsPLL Driver OutputsRF Freq.
    RF Freq.
    (mm x mm)
    MAX9988 YesYes1500220014.219.54.75 to 5.251625.0 x 5.0

    Pricing Notes:
    This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.
    Request Reliability Report for: MAX9988 
    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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