ltc2000-16

Hi! I have problem iwth using ltc2000-16. SFDR = 47dBc(fout = 270MHZ, fdac=1200MHz) Rfsadj = 500Ω, Rload = 12,5Ω, LIN_DIS = 0, LIN_ GN = 75%, power is fine. What's the matter?

  • 0
    •  Analog Employees 
    on Jul 9, 2018 7:53 PM

    It looks like the 2nd is elevated.  What are you using to do the differential to single ended translation to drive the spectrum analyzer?  Can you post a picture of your setup?  What clock are you using?

  • Hi! We are using TC1-1-13MA+ to do the differential to single ended.

    DAC setup:

    0x0305

    0x0403

    0x040b

    Other registers by default.

    For the DAC clock using LMX2582. oscillator 156,25MHz +/- 20 ppm Best regards, Gleb.

    >EngineerZone

    >Re: ltc2000-16

    >reply from  Clarence.Mayott in  High-Speed DACs -  View the full discussion

  • 0
    •  Analog Employees 
    on Jul 11, 2018 9:30 PM

    Only a single transformer?  The TC1-1-13MA+  has an asymmetric construction so it isn't the best for 2nd.  We typically use that transformer with a second transformer to restore the balance and improve the symmetry.   Check out the DC2233:  

    DC2233A Evaluation Board | Analog Devices 

    We use the TC1-1-13 and an additional transformer to get better symmetry, better balance and better 2nd harmonic distortion. 

    Can you send a picture of your setup and schematic and layout there might be other issues as well.

    -Clarence

  • 0
    •  Analog Employees 
    on Aug 2, 2018 4:05 PM
    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

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    EZ Admin