This work proposes a new architecture named “Dithered hybrid multi-stage noise shaping-error feedback modulator with cancellation transfer function” sigma-delta modulator for audio digital-to-analog (D/A) converter. Multi-stage noise shaping (MASH) architecture possesses noise shaping technique which produces high signal-tonoise ratio with greater stability. Error feedback modulator (EFM) has an advantage of providing greater stability with time varying inputs. The state-of-the-art technology under the name of dithered hybrid MASH-EFM with cancellation transfer function (CTF) sigma-delta modulator provides better noise shaping, high SNR and greater stability than the traditional sigma-delta architecture. MATLAB simulation shows that 1st order Dithered hybrid MASH-EFM SDM with CTF achieves high signal-to-noise ratio (SNR) of 184db over 22kHz bandwidth when oversampling ratio (OSR) is 128, which is approximately equal to the SNR of 2nd order traditional architecture. Other performance parameters like signal-to-quantization noise ratio (SQNR), effective number of bits (ENOB), signal-to-noise and distortion ratio (SNDR) and dynamic range (DR) are also recorded in this work. Noise transfer function (NTF) graphs are also plotted for traditional and proposed architectures.
Khalid Ijaz, Khawar Khokhar, , Muhammad Adnan, , Awais Saeed. (2018) A Novel First Order Dithered Hybrid MASH-EFM with Cancellation Transfer Function Sigma-delta Modulator for Eight-bit Audio DAC, , Proc. of the PAS: A; 55,, Issue 1.
