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**Dynamic characterization**- 1. Fourier Transform
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From the spectrum results the following parameters can be calculated:

Where c stands for the amplitude of the carrier bin (the "signal", d for the sum of all distorsion bins and n for the sum of all noise bins. The position of the carrier bin is equal to the number of periods of the carrier in the captured window. In the plot (see 1. Fourier Transform) the number of periods is 5 and the bin position of the carrier is 5 (bin 0 is the DC component).

SINAD stands for Signal to Noise and Distorsion. It is the ratio signal (or carrier) and all other spectrum bins. The Effective Number of Bits (ENOB) is calculated from the SINAD. The theoretical maximum signal-to-noise-and-distorsion for a linear ADC with a full-scale sine-wave input derives from quantization noise (or resolution for a DAC) and is defined as 20 * log(2^(n-1) x sqrt(6) ), or about 6.02n + 1.76 dB. With a perfectly linear but noisy system SINAD and SNR are interchangeable.

The Signal to Noise ratio or SNR stands for the ratio signal (or carrier) and all noise bins. Noise bins are all bins not being the carrier, a harmonic or DC.

SNR usually degrades as frequency increases because the accuracy of the comparator(s) within the ADC degrades at higher input slew rates. This loss of accuracy shows up as noise at the ADC output. In an A/D converter, noise comes from four main sources: (1) quantization noise, (2) noise generated by the converter itself, (3) application circuit noise and (4) jitter.

Quantization noise results from the quantization process, the process of assigning an output code to a range of input values. The amplitude of the quantization noise decreases as resolution increases because the size of an LSB is smaller at higher resolutions, which reduces the maximum quantization error. The theoretical maximum signal-to-noise ratio for a linear ADC with a full-scale sine-wave input derives from quantization noise (or resolution for a DAC) and is defined as 20 * log(2^(n-1) x sqrt(6) ), or about 6.02n + 1.76 dB. With a perfectly linear but noisy system SINAD and SNR are interchangeable. Application circuit noise is that noise seen by the converter as a result of the way the circuit is designed and laid out. SNR increases with increasing input amplitude until the input gets close to full scale. The SNR increases at the same rate as the input signal until the input signal approaches full scale. That is, increasing the input signal amplitude by 1 dB will cause a 1 dB in increase in SNR. This is because the step size becomes a smaller part of the total signal amplitude as the the signal amplitude increases. When the input amplitude starts approaching full scale, however, the rate of increase of SNR vs. input signal decreases. SNR performance decreases at higher frequencies because the effects of jitter get worse.

The Total Harmonic Distorsion or THD is the ratio distortion bins and signal (or carrier). Harmonics are mutiples of the carrier. The number of bins to be signed as harmonic can be configured with parameter o of the command CALCOPT_DYN. The default number of harmonic bins is 7. Harmonics can be mirrored bins.

The spurious free dynamic range is the difference in dB between the signal and the any other signal (spurious) in the spectrum with the highest peak.

The highest distorsion bin.

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