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. 24, 2008
Filed:
Apr. 12, 2006
Masahiro Suzuki, Osaka, JP;
Masahiro Suzuki, Osaka, JP;
Fuetrek Co., Ltd., Osaka-shi, JP;
Abstract
An A-D converter utilizing V-F conversion is realized that is capable of performing A-D conversion with high precision without increasing conversion frequency. Two VCOs are provided to find a V-F conversion value that is less than a period of the main VCO by making use of a period difference between the two VCOs. By counting the number of pulses in a pulse signal that is output from a BASE-VCO with a counter, a high order bit of a digital signal is generated. A low order bit, on the other hand, is generated by calculating, for each sampling period, a phase difference from the beginning of a sampling period until a first pulse generation in the sampling period for the output of the BASE-VCO by a third register and second and third subtracters, based on the number of pulses in the output of the BASE-VCO contained in a period from a current activation time point of sampling signal Ps to a time point at which phases of outputs of the BASE-VCO and JAW-VCO match.