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:
Dec. 16, 2008
Filed:
Jul. 30, 2007
Hideyuki Yamakawa, Tokyo, JP;
Yukiyasu Tatsuzawa, Tokyo, JP;
Takayuki Mori, Tokyo, JP;
Takahiro Nango, Tokyo, JP;
Hideyuki Yamakawa, Tokyo, JP;
Yukiyasu Tatsuzawa, Tokyo, JP;
Takayuki Mori, Tokyo, JP;
Takahiro Nango, Tokyo, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
An integrated circuit includes an AD converter and a self-test circuit configured to test the AD converter. The self-test circuit includes a clock generator which generates a clock for allowing the AD converter to AD-convert an external sine wave signal externally input, a sine wave generator which generates an internal sine wave signal in digital form, a subtractor which determines a differential signal between the AD-converted external sine wave signal and the internal sine wave signal, a PLL device which allows a phase-locked loop receiving the differential signal as an input to control a phase of the internal sine wave signal such that the internal sine wave signal is in phase with the external sine wave signal, and a root mean square calculator which calculates a root mean square of the differential signal to generate a diagnostic signal corresponding to the AD converter.