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. 25, 2008
Filed:
Jul. 19, 2006
Edward Arthur Keehr, Pasadena, CA (US);
Edward Arthur Keehr, Pasadena, CA (US);
QUALCOMM Incorporated, San Diego, CA (US);
Abstract
Techniques for performing ΣΔ modulation with offset in order to reduce out-of-band quantization noise are described. In an exemplary oversampling DAC that implements ΣΔ modulation with offset, an interpolation filter performs upsampling and interpolation filtering on data samples to generate input samples. A summer adds an offset to the input samples to generate intermediate samples. The offset alters the characteristics of the quantization noise from a ΣΔ modulator and may be selected to obtain the desired quantization noise characteristics, to retain as much dynamic range as possible, and to simplify the removal of the offset. The ΣΔ modulator performs upsampling and noise shaping on the intermediate samples and provides output samples. An offset removal unit removes at least a portion of the offset from the output samples in the digital or analog domain. A DAC converts the output samples to analog.