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LMX2594: Instrument to measure Frequency Swithcing Time

Derek Wang
Intellectual 615 points
Part Number: LMX2594

Hi TI Experts, 

What kind of RF instrument I should use to measure the frequency switching time like below figure?

I only have Spectrum Analyzer, High Speed Osillscope.

  • 0
    TI__Mastermind 28011 points

    Here are 3 methods:

    1.  Lock detect Method (Preferred)

    Set LD_TYPE="VCOCal", MUXout_LD_SEL="Lock Detect", LD_DLY=0.   Then the MUXout pin will have low pulses corresponding to when the VCO calibration is running.  Note that this is only for the VCO calibration and does not include the analog PLL settling time

    2.  Vtune Method

    Observe the Vtune voltage with an oscilloscope.  However, realize that even a 1 Mohm load might impact the locking and also that during the VCO calibration, the tune voltage is held near about 1.5 V.

    3.  0 Hz SA method

    Set the spectrum analyzer span to 0 Hz.  Then the sweep time controls the time base and the resolution.  Then you can get an indication of power vs. time.   When you are at the final frequency power is maximized.

    Regards,
    Dean