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:
Nov. 06, 2001
Filed:
Nov. 09, 1998
Jonathan H. Fischer, Blandon, PA (US);
Wenzhe Luo, Allentown, PA (US);
Zhigang Ma, Bethlehem, PA (US);
Agere Systems Guardian Corp., Orlando, FL (US);
Abstract
A digital phase locked loop includes a digital phase detector which provides a magnitude control signal to adjust the step size of up and down adjustments in the phase/frequency of a digitally controlled oscillator, resulting in shorter lock-in or acquisition time and smaller jitter as compared to conventional digital phase locked loop devices. In the disclosed embodiments, the digital phase detector includes multiple bit shift registers in both the up and down directions to count or measure a number of up or down minimum width pulses and provide a pulse magnitude control based on the value of the shift registers to the digitally controlled oscillator. The digitally controlled oscillator includes a charge pump and voltage controlled oscillator. In one embodiment, the charge pump provides programmable control over its output current pulses to a capacitor which controls the output frequency of the voltage controlled oscillator.