Linearity enhancement of multibit ΔΣ A/D and D/A converters using data weighted averaging

Author

Baird, Rex T. ; Fiez, Terri S.

Author_Institution

Crystal Semicond. Corp., Austin, TX, USA

Volume

42

Issue

12

fYear

1995

fDate

12/1/1995 12:00:00 AM

Firstpage

753

Lastpage

762

Abstract

A dynamic element matching algorithm, data weighted averaging, is introduced for use in multibit ΔΣ data converters. Using this algorithm, distortion spectra from DAC linearity errors are shaped by first-order noise shaping, resulting in a dynamic range improvement of 9 dB/octave when DAC errors dominate. Combining this technique with random dithering nearly eliminates the aliasing of the DAC errors into the baseband. Simulations show that with only 1% element matching 110 dB signal-to-noise ratio (18 b) is achieved for a third-order 3-b modulator with an oversampling ratio of 128

Keywords

digital-analogue conversion; electric distortion; sigma-delta modulation; 3 bit; aliasing; data weighted averaging; distortion spectra; dynamic element matching algorithm; dynamic range improvement; first-order noise shaping; linearity enhancement; multibit ΔΣ A/D converters; multibit ΔΣ D/A converters; oversampling ratio; random dithering; signal-to-noise ratio; third-order modulator; Baseband; Dynamic range; Feedback; Heuristic algorithms; Linearity; Logic; Noise shaping; Quantization; Signal processing algorithms; Signal to noise ratio;

fLanguage

English

Journal_Title

Circuits and Systems II: Analog and Digital Signal Processing, IEEE Transactions on

Publisher

ieee

ISSN

1057-7130

Type

jour

DOI

10.1109/82.476173

Filename

476173