DEWE-43A
TECHNICAL REFERENCE MANUAL
Image 3: Sample rate 51.2kS/s to 102.4kS/s
Image 4: Sample rate 102.4kS/s to 200kS/s
The ADC samples at 64, 128 or 256 times the data rate (depending on the adjusted sample rate).
Frequency components above one half of the oversampling rate (> 32, 64 or 128) can alias. Most of this
frequency range is rejected by the digital filter. The filter can not reject components that lie close to
integer multiples of the oversampling rate because it can not differentiate these components from
components between 0 Hz and the Nyquist frequency. That means, if the sample rate is 100 kS/s and a
signal component is between 50 kHz and 12.8 MHz (128 x 100 kHz), this signal will be aliased into the
passband region of the digital filter and is not rejected. The analog filter removes these components
before they get to the digital filter and the sampler.
DEWE-43A V20-2
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