Integral Noise Shaping for Quantization of Pulse-Width Modulation
Integral noise shaping (INS) is introduced as a method for quantization of pulse-width modulation (PWM), which takes into account the fact that it is PWM that is being quantized. The quantization errors are noise shaped by analytically integrating the ideal and quantized PWM waveforms. The resulting quantizer can noise shape the rising and falling edges of two-sided PWM through the same quantization process. This effectively doubles the oversampling ratio without any changes to the switching or clock frequency. This method results in a tremendous improvement in signal-to-noise ratio (SNR). It is particularly useful for high-end digital audio amplifiers.:
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