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. 28, 2001
Filed:
Mar. 24, 2000
Robert P. Ryan, Mission Viejo, CA (US);
George S. Bouchaya, Mission Viejo, CA (US);
Western Digital Corporation, Lake Forest, CA (US);
Abstract
Disclosed is a method in a disk drive that allows the functionality of a single high-resolution DAC to be replicated with a pair of lower-resolution DACs that are operated in a unique manner that provides monotonic behavior and reduces both differential and integral non-linearity. The two lower-resolution DACs take up substantially less space that one higher-resolution DAC when implemented in a semiconductor die. The method combines coarse values from one DAC with fine values from the other DAC to form a combined analog output signal within operational segments that collectively span a range of N-bit demands. The method operates such the operational segments overlap one another by 50 percent, with an endpoint of each operational segment ending near a center of an overlapped operational segment. The method's overlapping relationship tends to cause the combined analog output voltage to vary monotonically, by maintaining the X-bit command and only varying the Y-bit command whenever possible for small changes in the combined analog output signal.