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:
Jan. 23, 2007
Filed:
Dec. 08, 2005
John L. Melanson, Austin, TX (US);
Melvin L. Hagge, Round Rock, TX (US);
Brian David Trotter, Austin, TX (US);
John L. Melanson, Austin, TX (US);
Melvin L. Hagge, Round Rock, TX (US);
Brian David Trotter, Austin, TX (US);
Cirrus Logic, Inc., Austin, TX (US);
Abstract
A centered-pulse consecutive edge modulation (CEM) method and apparatus provides a pulse output that advantageously exploits the full edge update rate of the CEM while providing substantially centered pulses. The method and apparatus also operate without substantial delay in the input control path. The apparatus includes a delta-sigma noise shaping modulator followed by a CEM that receives an output of the delta-sigma modulator quantizer. A non-linear correction signal is applied with polarity alternating at each edge and is applied to the quantizer input or is designed into the quantizer transfer function. The non-linear correction signal compensates for the noise-shaping modulator output such that the expected rising edge and falling edge widths of the CEM output pulses are substantially equal with respect to a DC input to the delta-sigma modulator.