Optimal design method of delta-sigma modulator for digital audio amplifier

In recent years, low-power digital audio (Class-D) amplifiers have been widely used in portable digital devices such as smart phones and tablet PCs. The ΔΣ modulator is a key component of the Class-D amplifier, and higher-order ΔΣ modulators provide the advantages of better performance and lower cost. For higher-order ΔΣ modulator design, it is imperative to determine the optimal design parameters for realizing the maximum SNR while maintaining system stability, which requires the expertise of an experienced designer. To overcome this problem, we propose a new fully automatic optimal design method based on simulated annealing (SA). Compared with the conventional steepest descent optimal design method, this method provides better performance and higher system stability.