And if you're wondering why it's only ever toggling between -1 and 0, it's
because most ADCs are biased centred around -0.5, not 0. This is so that
they're symmetrical in positive and negative swing (remember two's complement
for an 8 bit number will be -128 to +127). Some will let you adjust
On 9/20/2016 3:55 PM, David MacMahon wrote:
Hi Adam,
A little bit of noise (a step or several rms) is a cure for many ADC
ills, and is widely practiced under
the term "dithering". It's usually nicest if the dithering waveform can
be arranged to fall outside the
signal band of interest (yet
hi adam,
the effect you are seeing is visible on many adc's - some digital noise
gets into the analog input,
and is often easy to see when there is no signal input, especially when the
adc's DC offset
happens to lie near the boundry of two ADC steps (then any noise will cause
the ADC to toggle).
Hi, Adam,
I haven't looked at the spectral content of a terminated input before so I
don’t have any comparative results, but I think the spikes you are seeing are
caused by mismatched gains and/or offsets of the ADC’s interleaved cores (I
think there are a total of 8 cores, also called
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