--- In "PeterElliot" <> wrote:
>
> --- In "j.chitte" <j.chitte@> wrote:
> >
> > Not getting anyway fast with this.
> >
> > I see continuous +/- 2mV which is expected 2LSB variations
however
> > frequent +/- 6mV spikes are spoiling my day.
> >
> > Nobody here tried to get accurate ADC on the 7250?
> >
> > Thx.
> >
>
> What sample rate are you using? I tend to oversample and average
my A/
> D readings to reduce this type of spurious periodic noise. This
all
> depends on the signal being measured and the current sample rate.
>
Thanks,
yes I can use a mean to reduce the peaks but I want to get noise down
to a minimum before I start to paper over the cracks.
> Without knowing the exact design, the causes for these noise
spikes
> are difficult to pin down, but if you're refering to the A/D on
the
> TS-72xx board itself I doubt that the layout was aimed at getting
the
> full performance of the A/D - I don't know if they implemented a
> separate analogue ground plane around the chip, It may be that
it's
> picking up noise from the digital circuitry.
>
> PJE
>
I am starting to suspect that it's the ethernet driver loading the on
board power rails.
It's true the board layout could go further , this is why I was
asking if anyone had direct experience of noise levels , this would
help me see if it is a defect in my work or I am up against a
limitation of the TS board.
Some input from Technologic may be helpful here.
Many thanks for comments.
/jacques
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