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:
Sep. 28, 1999
Filed:
Oct. 31, 1997
John Charles Ciccone, Scottsdale, AZ (US);
Stephen D Nemetz, Gilbert, AZ (US);
VLSI Technology, Inc., San Jose, CA (US);
Abstract
An electronic device is delineated comprising, in combination, a Phased Lock Loop (PLL) having a charge pump, and a mixed signal circuit coupled in parallel to the charge pump. The mixed signal circuit includes analog circuitry for adding charge to and removing charge from capacitors in a Low Pass Filer (LPF) of the PLL. The mixed signal circuit also includes digital circuitry for controlling the initiation and termination of both the charging and discharging operations carried on by the analog portion of the mixed signal circuit. Upon a significant change in system frequency, the mixed signal circuit first fully discharges and then rapidly charges the capacitors in the LPF in a manner which results in a significant reduction in PLL locking time.