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

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
Anonymous
Not applicable

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.

0 Likes
1 Reply
SampathS_11
Moderator
Moderator
Moderator
250 sign-ins 250 solutions authored 5 questions asked

You can post your project, and we can take a look into it.

0 Likes