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:
May. 25, 2010
Filed:
Jun. 13, 2008
Alexander Wormer, Munich, DE;
Harald Sandner, Marzling, DE;
Alexander Wormer, Munich, DE;
Harald Sandner, Marzling, DE;
Texas Instrumentsdeutschland GmbH, Freising, DE;
Abstract
A phase locked loop has a digitally controlled oscillator (DCO) for generating a DCO output signal (f), a clock divider coupled to the DCO and receiving the DCO output signal and outputting a feedback clock signal (f), and a phase frequency detector (PFD) coupled to the DCO and controlling the DCO by a DCO control signal (d). The PFD has a first input for receiving the feedback clock signal (f), a second input for receiving a reference clock signal (f), and comprises a frequency detection stage (FD) adapted to calculate a frequency difference between the feedback clock signal (f) and the reference clock signal (f) in a frequency detection mode and to adjust the DCO control signal based on said frequency difference, a phase detection (PD) stage for calculating a phase error between the feedback clock signal and the reference clock signal in a phase detection mode, and a switch for switching between the frequency detection mode and the phase detection mode upon the frequency of the feedback clock signal reaching a predetermined value.