6 Replies Latest reply on Dec 14, 2018 1:34 AM by ksje14_3880586

    ADC, with vref bypassed, is only creating approximately 1500 valid samples

    ksje14_3880586

      Hello,

       

      I have a problem with SAR ADCs on my PSoC 5LP.

       

      I am currently using the following setup where an ADC is supposed to sample 6000 samples from a maximum peak detector.

      PeakDetector.PNG

      The SAR ADC can sample 6000 samples without any issues as long as I have not set it to vref, bypassed mode.

      Now I don't know if this is normal behavior, so I am wondering if I can fix this somehow. Here is an image of my data:

      sar_adc_data.jpg

      I have two signals that I sample, this one only reaches approximately 1450 before it returns 0 for all other samples.

      My other signal goes a bit above 1500 in samples. But if I set it to vref mode it can easily give me more than 1500 valid  samples.

       

      Both SAR ADCs are configured the same way and so are the DMAs. The reason I need vref, bypassed mode is the higher sampling rate.

       

      So is this normal behavior?

       

      Regards, Kasper.