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:
Nov. 10, 1998
Filed:
May. 08, 1997
Shigetoshi Nakao, Komae, JP;
Hideki Kanayama, Atsugi, JP;
Toshio Murota, Hiratsuka, JP;
Masayuki Ukawa, Sagamihara, JP;
Burr-Brown Corporation, Tucson, AZ (US);
Abstract
A characteristic tone in a delta-sigma analog-to-digital converter is shifted out of an audible pass band without diminishing dynamic range or signal-to-noise ratio thereof by operating the digital-to-analog converter to measure its offset voltage. If the amplitude of the measured offset voltage exceeds a predetermined value, no dither signal is applied to the input of the delta-sigma modulator. If the measured offset voltage is less than the predetermined value, a positive DC dither voltage is added to the input voltage of the delta-sigma modulator if the measured offset voltage is positive, or is subtracted if the measured offset voltage is negative.