Each 4x increase in a factor adds 6 dB and 1 bit of resolution.
SNRnew = SNRoriginal + (6 x Nbits), where (N= 1, 2, 3 or 4).
In the accompanying table, you will see the ideal Signal-to-Noise Ratio (SNR) and Effective Number of Bits (ENOB) results from oversampling. These absolute results are not realistic, but nevertheless a viable reference calculation.
Oversampling ratio options are: 4, 16, 64, or 256.
Derived Effective Number of Bits (ENOB)
Using the same theoretical SNR formula for general oversampling, you can derive typical SNR values for 4x, 16x, 64x and 256x oversampling.
Oversampling and averaging increase the ENOB, boosting the system’s SNR.
Practical SNR and derived ENOB values obtained through oversampling typically reflect more realistic system performance.
Warning
As the number of accumulated samples increases, the effectiveness of oversampling decreases due to ground noise.
If you need to work with Microchip Support staff directly, you can submit a technical support case. Keep in mind that many questions can be answered through our self-help resources, so this may not be your speediest option.
