1 Reply Latest reply on Aug 21, 2017 5:13 AM by samp

    PSoC 1 noise every 256 counts in DEL-SIG A/D. Why?

    james.dery

      We have implemented an LVDT driver/decoder and it works fine. Measuring resolution to .0001mm.

         

      However, as you slowly scroll up through the 14-bits worth of counts produced by the A/D converter, there will be spots of noise every

         

      256 counts where the noise goes to +/- 20 counts instead of +/- 1 count.  This is not the normal noise at the

         

      ends of the A/D range on the delta-sigma converter but a very repeatable noise in 64 places over the 16k counts.

         

      The LVDT circuit was removed and a pure DC voltage was put into the A/D instead: Same noise spots so I'm convinced

         

      it's inside the chip.  Any ideas where this noise is coming from? Also, I'm not the original programmer of the device. I

         

      am a test engineer.  Thanks.