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:
Jun. 01, 2010
Filed:
May. 25, 2006
Yuji Watabe, Osaka-fu, JP;
Yuji Watabe, Osaka-fu, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A testing circuit measures a center frequency of a clock signal outputted by a clock generator. The clock generator has a frequency modulator capable of (1) performing a frequency sampling accurately for the duration of modulation frequency and reducing the duration for frequency measurements, and (2) implementing proper testing of the down-spread controlling feature as one of the SSCG modulation functions by accurately determining the center frequency of the clock signal. The testing circuit measures a center frequency of a clock signal outputted by a clock generator by converting an analog modulation signal into a digital signal and outputting the digital signal, counting the period of the clock signal to obtain a count according to the digital signal outputted by the clock generator, and comparing the count with the predetermined specification values related to the center frequency of the clock signal to obtain and output a comparison result.