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. 07, 1998
Filed:
Aug. 12, 1997
Steven F Gillig, Roselle, IL (US);
Michael L Bushman, Hanover Park, IL (US);
Motorola Inc., Schaumburg, IL (US);
Abstract
A frequency synthesizer (10) including a synthesizer loop (12) with a fractional-N divider (14), and including a divider control circuit (18) and a combining circuit (22). The divider control circuit (18) provides a variable divide value (20) to the divider (14). The carry values of two accumulators (24, 26) having differing accumulator lengths are applied in parallel to the combining circuit (22). Each of the accumulators (24, 26) provides a portion of a desired fractional divide value (20). The combining circuit (22) also adds an integer divide value (36) to the fractional divide value (16). By coupling the accumulators (24, 26) in parallel, a high frequency resolution with minimal spurious frequencies is achieved, using a simple, low cost circuit.