Fig. 3
From: Design of low power energy efficient sigma-delta ADC for biomedical IoT applications
Illustration of quantization noise distribution in three scenarios: (1) Uniform quantization noise across the frequency spectrum up to the Nyquist frequency (Fs/2); (2) Redistribution of quantization noise using noise shaping, which pushes noise energy to higher frequencies beyond the Nyquist limit; (3) Application of noise shaping combined with digital filtering to remove high-frequency quantization noise, improving signal quality within the desired frequency range.
