4 Replies Latest reply on Jun 26, 2018 3:29 AM by vsrs

    DelSig ADC - ADC Reading over(under?)flows at 0V

    KTrenholm_1955226

      Hi all, I'm looking for some clarification on the readings I'm getting from the DelSig ADC component on a CY8CKIT-050.

       

      I have attached the project, there's some extra stuff going on with me experimenting with DMA and a bootloader, but the ADC is simply reading from the onboard pot on the test kit in single ended mode.  Input range is set to VSSA to VDDA and the buffer mode is "Bypass Buffer" but the problem exists on any of the buffer modes.

       

      What I'm finding is that when I hit the low end of the pot, 0V, my ADC value is appearing to underflow(?).  0V input results in values close to 0xFFFF.  The voltage is not going negative, at least according to my multi-meter measurement.  Can someone explain exactly why this is occurring, and what I would have to do to remedy the issue so 0V input results in 0x0000?

       

      Thanks in advance.