• State TI Thinks Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 2 answers
  • Subscribers 21 subscribers
  • Views 736 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LMX2594EVM: Testing LMX2594EVM in automatic ramping mode

deva kumar
Prodigy 10 points

Part Number: LMX2594EVM
Other Parts Discussed in Thread: LMX2594, LMX2492, LMX2491

Iam testing the LMX2594 Evaluation module using TICS Pro software. It is required to test in automatic ramping mode with frequency from 12 to 12.4 GHz i.e. 400MHz in 100 microseconds. Please provide the solution or setup details of the ramp GUI.

  • 0
    TI__Guru** 122320 points

    Hi Deva,

    Are you looking for linear frequency ramp or a staircase ramp is acceptable? Below is an example of staircase ramp.

  • 0 in reply to Noel Fung
    Prodigy 10 points

    Hi Noel,

    I have to generate linear frequency ramp or continuous sawtooth waveform 12 to 12.4 GHz i.e. 400MHz in 100 microseconds

  • 0 in reply to deva kumar
    TI__Guru** 122320 points

    Hi Deva,

    This is not possible with LMX2594, you need to use standalone PLL (such as LMX2492) + external VCO. 

  • 0 in reply to Noel Fung
    Prodigy 10 points

    Hi Noel,

    thank you for the response

    1. I would like to know, why it is not possible with LMX2594

    2. For the alternate solution you have suggested, please suggest required external VCO part number.

    3. I have a similar requirement to generate linear frequency ramp from 4.3 to 4.6 GHz i.e. 300 MHz in 100 microseconds. Please suggest PLL Synthesizer.

  • 0 in reply to deva kumar
    TI__Guru** 122320 points

    Hi Deva,

    LMX2594 uses 7 VCOs to support 7.5GHz to 15GHz frequency range. The tuning range of each VCO is approx. 1GHz.

    Each VCO is actually divided into 256 sub-bands. As a result, whenever we change the VCO frequency, we need a calibration (automatic) to get the VCO tuned to the correct band. If the frequency change is small (<100MHz), a calibration may not necessary, Vtune is able to change the frequency. So, the linear ramp range is limited to 100MHz. 

    I don't have a suggestion for the external VCO, we do not have standalone VCO product.

    LMX2491 is the lower frequency variant of LMX2492, it can support up to 6.4GHz.