Title :
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
fDate :
12/1/1995 12:00:00 AM
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;
Journal_Title :
Circuits and Systems II: Analog and Digital Signal Processing, IEEE Transactions on
