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. 29, 2011
Filed:
Mar. 01, 2010
Ahmed Mohamed Abdelatty Ali, Oak Ridge, NC (US);
Andrew Stacy Morgan, Stokesdale, NC (US);
Ahmed Mohamed Abdelatty Ali, Oak Ridge, NC (US);
Andrew Stacy Morgan, Stokesdale, NC (US);
Analog Devices, Inc., Norwood, MA (US);
Abstract
Calibration methods and structures are provided for pipelined analog-to-digital converter systems. They are arranged to process samples of the digital codes with an algorithm that is preferably configured to repeatedly update an estimate of the transfer function with the difference between one of the input signals and the analog equivalent of the corresponding digital code. The calibration methods and structures are further configured to calibrate the transfer function of the converter stage wherein the samples are selected in accordance with various steps. These steps can include the step of injecting dither signals into a flash portion and an MDAC portion of the converter stage to thereby maintain dynamic range. They can also include the step of limiting the samples to those processed through a selected subrange of the subranges. They can further include the step of limiting the samples to those in which the absolute value of the input signals is less that 0.25 of the selected subrange and the absolute value of the dither signals is less that 0.25 of the selected subrange. If the selected subrange is not a central subrange, the steps can further include the step of shifting the samples by a distance between the selected subrange and the central subrange.