• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 21 subscribers
  • Views 195 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.

LMX2572: LMX2572: LXM2572EVM: Generating Up-Chirp

abc
Prodigy 60 points
Part Number: LMX2572
Other Parts Discussed in Thread: , LMX2491

Tool/software:

Hi,

I had been experimenting with the LMX2572EVM with TICS pro and my goal is to generate:

a. 1GHz bandwitdth up-chirp within 100 usec,

b. then a sleep time of 100usec

then repeat a,b,a,b,a,b,....

I am using the automatic ramping feature. I had been experimenting with TICS Pro and here are my settings.

If I could get some guidance on how to achieve my goal, that would be great.

In case LMX2572 is not suitable for what I am trying to achieve, any recommendations for a suitable TI chip?

Thanks!

  • 0
    TI__Guru** 109470 points

    Hi There,

    Do you need linear frequency sweep between 3.2GHz and 4.2GHz?

    LMX2572 can support linear sweep with a very limited range, approx. 50MHz at VCO frequency.

    Below plot is a linear frequency sweep.

    If wider sweep range is required, LMX2572 can still support but there will be several VCO calibration during the sweep period. The result is not a linear sweep.

  • 0 in reply to Noel Fung
    Prodigy 60 points

    Hi. thanks for your reply. Yes, I will need a Linear Frequency Sweep, Here is what I am trying to achieve (used MSPaint on this)

    I will be using a frequency sweep from 3.2GHz to 4.2GHz

    T1 - 1GHz upchirp (from 3.2 to 4.2GHz) within 100usec.

    T2 - (stay at 3.2GHz) for 100usec

    T1 - 1GHz upchirp (from 3.2 to 4.2GHz) within 100usec.

    T2 - (stay at 3.2GHz) for 100usec

    do you think this is something achievable with LMX2572? or are there any other alternatives/solutions?

    Thanks!

  • 0 in reply to abc
    TI__Guru** 109470 points

    Hi There,

    To achieve 1GHz linear sweep you need to use discrete PLL + VCO.

    We have the LMX2491 (www.ti.com/.../LMX2491), which can support up to 6.4GHz VCO. This device has a built-in ramp engine similar to LMX2572. You can configure this engine to create the ramp you mentioned.

    For example, below configuration gives you the ramp you want.