Design and implementation of an audio analog to digital converter using oversampling techniques

Presents a sigma delta converter that over samples the analogue signal to obtain high-resolution digital data. A second order 1-bit sigma delta modulator will be considered as the front-end A/D converter and designed in switched current S²I technique to achieve 1-bit quantizing at 1.024 MHz. The subsequent decimation filter reduces the sampling rate by a factor of 64 and guarantees a stop band attenuation of 80 dB. The modulator was implemented in a 0.6 μm three metal layer digital CMOS process from single 3.3 V power supply and the decimation filter is simulated under signal processing workstation SPW. The measured dynamic range of the modulator is over 8 bits