Other Parts Discussed in Thread: LMX2491, LMX2492
Tool/software:
Greetings,
I am working with the IWR6843 and I am trying to understand how it generates fast chirps. Please correct me if I am wrong here, but so far I have understood that the clean up PLL serves to have a pretty stable reference for the frequency synthesizer, which is in essence a fractional PLL and the modulation is controlled by the timing engine. However, I don't understand why the timing engine has to be outside the Frequency Synthesizer. Also I would like to know which components are used to build this subsystem and if they are available. I have checked some PLL such as LMX2491 LMX2492 and the maximum slope is 200 MHz/us :
Ramp Slope = f_PD* Rampx_inc/ 2^24, so for the maximum value of Rampx_inc will be 200 MHz/us
Lastly, I would like to ask how to properly set up the ADC starting time, since the tutorial on how to program chirps: https://www.ti.com/lit/an/swra553a/swra553a.pdf?ts=1742889622275 mentions a calculator, but I would like to know how it is computed to check the numbers provided are correct. What would happen if the ADC time was not long enough, the chirp linearity would be affected, but would it still be able to measure velocity?
Thank you very much for your help.
Best Regards,
Daniel
