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:
Oct. 17, 1989
Filed:
Aug. 29, 1988
Hitachi, Ltd., Tokyo, JP;
Abstract
In a two-step parallel analog to digital converter of the type in which a first flash-type A/D converter determines the upper significant bits of a digital signal output having a desired number of bits and after a quantizing error of the first flash-type A/D converter has been determined from the difference between a value obtained by reconverting the upper significant bits to an analog value and the input analog value a second flash-type A/D converter subjects the quantizing error to A/D conversion to determine a digital output of the remaining lower significant bits, a gain correcting circuit is additionally provided to automatically establish a gain of a D/A converter for reconverting the upper significant bits to an analog value on the basis of a reference voltage applied to the first flash-type A/D converter. Moreover, a reference voltage generating circuit is additionally provided to establish upper and lower reference voltages of a second flash-type A/D converter for determining lower significant bits on the basis of the step voltage of the DAC output.