Sources of Noise and Spurs in DDS
The model of the noise and spurs in the DDS has six sources. These sources are depicted symbolically in Figure 5.1. The sources are: the truncation of the phase accumulator bits addressing the sine ROM (eP), a distortion from compressing the sine ROM (eCOM), the finite precision of the sine samples stored in the ROM (eA), the digital-to-analog conversion (eDA), a post-filter (eF), the phase noise of the clock frequency (nclk), and the frequency error (Δf). The frequency error (Δf) causes a frequency offset (2.2), but not noise and spurs.
KeywordsDiscrete Fourier Transform Phase Noise Clock Frequency Quantization Error Clock Signal
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