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:
Sep. 03, 2013
Filed:
Mar. 31, 2010
Robin Matthew Tsang, Austin, TX (US);
Eric J. Swanson, Buda, TX (US);
John L. Melanson, Austin, TX (US);
John Christopher Tucker, Austin, TX (US);
Robin Matthew Tsang, Austin, TX (US);
Eric J. Swanson, Buda, TX (US);
John L. Melanson, Austin, TX (US);
John Christopher Tucker, Austin, TX (US);
Cirrus Logic, Inc., Austin, TX (US);
Abstract
An offset correction circuit removes DC offset from an analog audio output signal by comparing transitions of digital audio values to which the analog output signal is related to the output of a monitor that monitors the analog output signal. The monitor may be a zero-crossing detector and the transitions of the digital signal that are compared may be transitions of the most-significant bit (MSB) of the digital audio values. A filtering algorithm or filter circuit may be used to average a result of the comparison of the transitions, so that the offset is slowly and accurately removed. A chopped or autozero comparator may be used to further reduce error in the offset determination.