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:
Oct. 19, 2010
Filed:
May. 04, 2007
James Toner Sundby, Tracy, CA (US);
James Toner Sundby, Tracy, CA (US);
Exar Corporation, Fremont, CA (US);
Abstract
A PLL includes control circuitry adapted to detect missing pulses of a reference clock and to control an output voltage of a charge pump disposed in the PLL accordingly. A signal generated in response to the detection of a missing pulse is pulse-width limited and applied to the charge pump during a first period. The detection of the pulse-width limited signal is used to generate a first slew signal that is also pulse-width limited and applied to the charge pump during a second period. The detection of the first slew signal is used to generate a second slew signal that is also pulse-width limited and applied to the charge pump during a third period. The amount of current supplied by the charge pump during the second charging period is equal to a sum of currents withdrawn by the charge pump during the first and third time periods.