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:
Aug. 19, 2008
Filed:
Dec. 15, 2006
Martin Andersson, Lund, SE;
Lars Sundstrom, Lund, SE;
Martin Andersson, Lund, SE;
Lars Sundstrom, Lund, SE;
Abstract
A method and apparatus taught herein provide a digital-to-analog converter (DAC) for use in a conversion feedback path of a sigma-delta type analog-to-digital converter (ADC). The DAC uses current pulse shaping to generate a conversion feedback signal in each feedback cycle of the ADC that provides a consistent charge transfer for accurate digital conversion and has a controlled current pulse shape. In one or more embodiments, the DAC includes a capacitor circuit for charge storage and transfer and a (series) resistive circuit having variable resistance for current pulse shape control. In at least one embodiment, current pulse control limits a peak current of the conversion feedback signal, thereby reducing DC power consumption and gain-bandwidth (GBW) and slew rate requirements of the ADC's integration amplifier, and limiting residual (ending) current in each feedback cycle, which yields commensurate gains in (feedback cycle) clock jitter insensitivity.