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:
Mar. 12, 2002
Filed:
Sep. 20, 2000
James Gregory Mittel, Lake Worth, FL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A digital tuning circuit ( ) for a filter ( ) has a filter input and a filter output and employs a switchable element array ( ). The filter includes a tuning signal generator ( ) that generates a tuning signal ( ) that is delivered to the filter input and a clock circuit ( ) that generates a periodic stream of pulses. The digital tuning circuit includes a delay circuit ( ), a phase comparator ( ) and an integrating up-down counter ( ). The delay circuit ( ) is responsive to the tuning signal generator ( ) and delays the tuning signal ( ) by a predetermined amount corresponding to the nominal delay through the filter ( ). The integrating up-down counter ( ) counts pulses in a first direction when the phase comparator ( ) generates the first value and counts pulses in a second direction, opposite from the first direction, when the phase comparator ( ) generates the second value. The integrating up-down counter ( ) generates a binary word having a value corresponding to a number of counts that the integrating up-down counter ( ) performs and is coupled to the switchable element array ( ) so that a number of switchable elements is electrically coupled to the filter ( ). The number of switchable elements corresponds to the value of the binary word.