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:
Sep. 08, 1998
Filed:
Feb. 12, 1996
Adrian Sherry, Dublin, IE;
Damien McCartney, Limerick, IE;
Analog Devices, Inc., Norwood, MA (US);
Abstract
An invalid reference detection circuit formed on a semiconductor chip having: reference input terminals adapted for coupling to a reference source external to the chip; a local reference source; and comparison circuit. The comparison circuit is responsive to the local reference source and a condition at the reference input terminals to detect an invalid condition at the reference input terminals and to produce an output signal indicative of the detected invalid condition. The invalid condition at the reference input terminals may be an open circuit condition at at least one of the reference input terminals, a condition when the voltage across the reference input terminals is below a predetermined minimum voltage level, a condition when the voltage across the reference input terminals is above a predetermined maximum voltage level, and/or a short circuit condition. An analog/digital conversion system is formed on a semiconductor chip together with the invalid reference detection circuit. The reference input terminals are adapted for coupling to the reference source external to the chip to the conversion circuitry to provide a reference for such conversion circuitry.