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. 25, 2004
Filed:
Jul. 09, 2003
Kenji Murata, Katano, JP;
Daisuke Nomasaki, Ibaraki, JP;
Abstract
The present invention provides a serial/parallel A/D converter which is capable of performing a high-speed and high-accuracy operation even in the case where an analog input voltage Vin greatly varies in a period between a previous sampling period in which the analog input voltage is held and the next sampling period, when converting the analog input voltage Vin input into a digital value. This serial/parallel A/D converter includes a lower-order reference voltage initializing circuit for initializing a lower-order reference voltage to an initialization voltage Vrc . The initialization voltage Vrc is generated as the lower-order reference voltage in an arbitrary period from the start of sampling of the analog input voltage until the start of a comparison operation for the lower-order reference voltage, the value of the lower-order reference voltage is changed from the value of the initialization voltage to a voltage value which is decided on the basis of higher-order code selection signals P C-P C from a higher-order code selecting circuit , and the value of the lower-order reference voltage which is decided on the basis of the higher-order code selection signals P C-P C is compared with the value of the analog input voltage.