A 105.5 dB, 0.49 mm2 Audio ΣΔ Modulator using Chopper Stabilization and Fully Randomized DWA

An audio Sigma Delta modulator achieves 105.5 dB dynamic range over 20 kHz audio bandwidth. A chopper stabilization technique is used in both the first integrator and the reference buffer to prevent degradation of the dynamic range and the peak signal-to-noise-plus-distortion-ratio due to flicker noise. A fully randomized data weighted averaging is used as a dynamic element matching technique to suppress the generation of spurious tones with a negligible increase in the in-band noise compared to conventional data weighted averaging. The chip was fabricated in 0.13 mu m CMOS technology (I/O devices) and occupies a small chip area of 0.49 mm(2). The total power consumption is 9.9 mW from a 3.3 V supply.