sheldon
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ZRSH001,
Unless you are doing something special with the SAR ADC you do not need a digital filter. For a SAR ADC with oversampling, you need to average the outputs. Store the value of out[n] in a register and add it to the output of the current conversion. out[n]=out[n-1]+ADCOUT
When you get done keep the top X number of bits that you need, where X is the number of bits of the ADC.
Unlike an oversampling ADC, oversampling of a Nyquist-Rate ADC provides limited improvements in the dynamic range. For example, a 2x oversample rate provides a 3dB improvement, a 4x oversample rate provides a 6dB improvement.
Note: this behavior is different than the behavior of a Delta-Sigma ADC.
Best Regards,
Sheldon
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