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. 20, 1988
Filed:
Jun. 12, 1987
Robert R Cordell, Tinton Falls, NJ (US);
Bell Communications Research, Inc., Livingston, NJ (US);
Abstract
A Phase/Frequency Locked Loop comprises a controllable oscillator which is phase locked with the clock of an incoming non-return-to-zero digital data signal. The controllable oscillator may be a voltage-controlled oscillator (VCO) or may be purely digital. The circuitry includes a novel digital phase and frequency detector which detects both frequency and phase error by sampling the incoming data stream at multiple phases of the output of the VCO (or the digital equivalent thereof). One of two binary disagreement signals are produced depending on the sense of the phase error. During periods of frequency error, the circuit automatically selects the proper type of disagreement signal (the leading-edge disagreement) required to achieve frequency lock.