• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 81 subscribers
  • Views 1304 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.

CCS/TMS320F28335: What is the maximum sampling rate of an ADC of F28335

bala naga lingaiah
Intellectual 570 points
Part Number: TMS320F28335

Tool/software: Code Composer Studio

I tried to sample a 1kHz signal through the ADC of F28335. I  am using the EPWM start of conversion initiated with 1MHz. So, I will get 1000 samples to construct the signal. But I am not getting the exact signal what I gave to the ADC. It is giving some random signals. I tested the EPWM it is giving 1MHz PWM output and ISR also triggering fine.  I tested with ADC signal of 50Hz and EPWM of 20kHz. It is giving nice waveform. Why I am unable to read the 1kHz signal. Is there any maximum frequency limit of the ADC that it can read?. Please help in this regard. 

  • 0
    TI__Guru 62975 points

    bala naga lingaiah,

    As shown in the datasheet, the ADC is capable of capturing samples at 12.5-MSPS:

    However, with a 150-MHz CPU, it can be difficult for the system to keep up with the full throughput of the ADC on a continuous basis.  For example, a 12.5-MSPS rate only allows for 150 / 12.5 = 12 cycles to process each sample.

    Based on your observations, I suspect that your software is not able to keep up with the sampling rate that you are using.

    -Tommy