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LMX2820: ambient temperature of RF PLL

Adrian Liu
Intellectual 2645 points
Part Number: LMX2820
Other Parts Discussed in Thread: LMX2694-EP

Hi Team,

My customer Samsung is asking for a RF PLL solution in RRU.

I want to confirm whether there are any devices available at a non-space level that can support an ambient temperature (TA) greater than 85 degrees and an output frequency greater than 3600 MHz? Samsung's board temperature currently reaches 95 or 105 degrees. Do we have a solution that can support these conditions?

If not, do we have a chip that can output 3600 MHz under a board temperature of 95/105 degrees?

BR

Adrian

  • 0
    TI__Mastermind 29272 points

    Hi Adrian,
    Most of our LMX devices are rated up to 85 deg C. 

    If Samsung requires up to 105 deg C they must look at auto grade where max temp is 105 or 125 deg C. 

    LMX2492Q1 appears to be the only RF PLL capable of meeting frequency requirement as well as temp. 

    Regards, 

    Vicente 

  • 0 in reply to vicente flores prado
    TI__Mastermind 29272 points

    Hi Adrian, 
    One more thing. 
    Can you please provide customer config (preferably a .tcs file) so I can estimate power dissipation and thus calculate ~junction Temperature? 
    I want to check if a different IC is actually needed here.

    T_J (Junction temp) = T_B (board Temp) + Phi_JB (provided in DS) * P 

    Regards, 

    Vicente 

  • 0 in reply to vicente flores prado
    TI__Intellectual 2645 points

    Hi Vicente,
    Okay, I will ask Samsung for the configuration file.

    The situation is as follows: Samsung's project has confirmed that the board temperature will exceed 85 degrees, but they can guarantee that the chip's Tj will not exceed 125 degrees. However, we previously gave Samsung feedback that when Ta exceeds 85 degrees and Tj is less than 125 degrees, the device can work normally but cannot guarantee performance because the VCO will be affected and cannot provide quantifiable indicators.

    Therefore, Samsung is currently consulting us on whether there is an RF PLL suitable for high-temperature scenarios.

    BR

    Adrian

  • 0 in reply to Adrian Liu
    TI__Guru** 108130 points

    Hi Adrian,

    LMX2694-EP can support higher temperature.