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:
Jul. 31, 2001
Filed:
Apr. 26, 2000
Christian Olgaard, Sunnyvale, CA (US);
Benny Madsen, Los Altos, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A frequency synthesizer with a digital frequency lock loop (FLL) having a fast frequency lock time uses a frequency counter circuit in the feedback loop to count the output signal frequency and produce frequency count data. A modulation control circuit provides modulation data and a corresponding modulation control signal for modulating the FLL signal source. A microprocessor processes the frequency count data along with the modulation data to provide a frequency control signal for controlling the nominal, or center, frequency of the FLL signal source. By processing these data together, thereby accounting for the amount of modulation applied to the FLL signal source, the center frequency can be maintained more consistently notwithstanding the presence of modulation within the feedback loop signal.