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. 11, 2007
Filed:
Aug. 02, 2005
William B. Wilson, Macungie, PA (US);
William B. Wilson, Macungie, PA (US);
Agere Systems Inc., Allentown, PA (US);
Abstract
In order to reduce the area of a charge pump PLL, one may separate proportional component and integral component of the loop filter voltage, and add additional circuitry so as to make the integral component appear as though it is affected by a much larger value of capacitance than is actually used. In an aspect, a current mirror may be used to subtract a portion of the integral component of the loop filter voltage from the total loop filter voltage. The difference signal is then used to drive an oscillator in the charge pump PLL. In another aspect, a third integrator or auto-calibration loop is used to set a center frequency of the oscillator.