The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 30, 2004
Filed:
Feb. 18, 2004
Weibiao Zhang, Plano, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A Sigma-Delta Analog-to-Digital Converter (ADC) having efficient dithering that removes the idle channel tones of the sigma-delta converter is disclosed herein. These idle channel tones are reduced or removed by stretching the threshold window of the multi-level quantizer. A dithering sequence is added by stretching the thresholds window randomly. The randomly stretched window destructs the periodicity of sigma-delta ADC modulator's output sequence and, thus, removes the idle channel tones. Compared with conventional methods, the Sigma-Delta ADC in accordance with the present invention has less SNR penalty and is simple to implement. Moreover, the sigma-delta ADC in accordance with the present invention has a higher allowed input dynamic range and higher signal-to-noise-plus-distortion-ratio (SNDR) than conventional modulator dithering schemes.