A High-Precision Audio Z-Δ D/A Converter

Design of a digital front-end module of Σ-Δ audio DAC is proposed in this paper, in order to meet the requirements of modern portable audio equipment with high sound quality, miniaturization and low power consumption. Two half-band filter and one CIC filter are used to design the interpolation filter with 128 times oversampling. The sigma-delta modulator selects the 3rd order 1bit quantization structure, and the system simulation is carried out under Matlab. The SNR of the whole DAC is 108 dB. Through FPGA verification, the test results show that the scheme is feasible.