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. 29, 1990
Filed:
Mar. 10, 1989
Shinri Fukuda, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A circuit for detecting a lock of a phase locked loop comprising a phase comparator receiving a first signal and a second signal for generating a phase difference signal, a waveform shaping circuit connected to receive the phase difference signal for generating an output signal when the phase difference signal indicates a phase difference exceeding a predetermined value, and a multi-stage counter having a frequency division function and having a reset input connected to receive the output signal of the waveform shaping circuit. An input control circuit is connected to receive the first signal and an output of the multi-stage counter and has an output connected to an input of the multi-stage counter for allowing the first signal to be applied to the multi-stage counter only when the output of the multi-stage counter is at a predetermined logic level. The output of the counter provides an lock output.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile