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. 28, 2014
Filed:
Sep. 14, 2012
Ryo Endo, Kanagawa, JP;
Jiro Shimbo, Kanagawa, JP;
Tomomitsu Kitamura, Kanagawa, JP;
Renesas Electronics Corporation, Kanagawa, JP;
Abstract
The present invention provides ABS precision improving means under ADPLL environment or environment close to the ADPLL environment and realizes shortening of process time of the ABS. In a digital frequency comparator in an ABS circuit, a DFF for storing an initial phase difference in a DPE signal output from a DPFD is prepared. Immediately after start of ABS operation, a DPE signal output from the DPFD is recorded as a signal expressing an initial phase difference in an internal circuit of the DPFD into the DFF. After that, the digital frequency comparator performs ABS by using a signal obtained by subtracting the initial phase error recorded in the DFF from an input DPE signal, thereby realizing high-speed and stabilized ABS operation.