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:
Jan. 03, 2012
Filed:
Mar. 04, 2009
Pasquale Lamanna, Villeneuve-Loubet, FR;
Nicolas Sornin, La Tronche, FR;
Pasquale Lamanna, Villeneuve-Loubet, FR;
Nicolas Sornin, La Tronche, FR;
Cambridge Silicon Radio Limited, Cambridge, GB;
Abstract
A phase-locked loop arranged to generate an output signal having a first frequency that is a static value times the frequency of a reference signal, the phase-locked loop comprising a signal generator arranged to generate the output signal, a divider arranged to receive the output signal and divide the output signal to form a feedback signal, the divider being arranged to vary the divisor by which the output signal is divided to cause the output signal to have a frequency that is said static value times the frequency of the reference signal, a comparison unit arranged to compare the feedback signal with the reference signal, one or more current generators arranged to output current pulses in dependence on said comparison, a summation unit arranged to receive the current pulses output by the current generator(s) and form a single current pulse therefrom and a loop filter arranged to filter the single current pulse to form a control signal for controlling the signal generator, the phase-locked loop being arranged such that the current generator(s) generate(s) a first current pulse dependent on a phase-difference between the feedback signal and the reference signal and a second current pulse whose magnitude and sign are dependent on an error in the feedback signal that is caused by the variation of the divisor, and the summation unit receives the first and second current pulses and stores an electrical charge representative of those current pulses and the summation unit outputs a single current pulse dependent on the electrical charge stored by the summation unit, said single current pulse being representative of a phase-difference that would have existed between the reference signal and the feedback signal if the feedback signal had been formed by dividing the output signal by said static value and not by the varied divisor.