Digital noise-shaping filter with real coefficients and method for making the same

摘要

A digital noise-shaping filter with real coefficients for delta-sigma data converters used in a digital amplifier, 1-bit digital/analog converter, 1-bit analog/digital converter and the like, and a method for making the same. The present digital noise-shaping filter has improved noise suppression performance and system stability and reduced calculation complexity. To this end, the digital noise-shaping filter comprises a noise transfer function expressed by NTF(z)=-1+a1z-1+a2z-2+LAMBD+aNz-N. The noise transfer function has optimum real coefficients or real coefficients approximating them.