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:
Jul. 26, 1994
Filed:
Jun. 30, 1993
Miroslaw Guzinski, Lawrenceville, NJ (US);
James L Lewandowski, Plainsboro, NJ (US);
Victor J Velasco, Montgomery, NJ (US);
Shianling Wu, Lawrenceville, NJ (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
A device (12), such as an A/D converter for generating successive codes, each in accordance with the level of an input analog voltage, may be tested to determine if all codes have been generated by applying a voltage V.sub.t having an amplitude that varies between 0 and V volts. The variation in the voltage V.sub.t is such that when the device (12) is operating properly, it will generate all of its codes during a predetermined interval. Each code generated by the device (12) is compared by a comparator (18) to the count of an n-bit counter (20) whose count is initialized at zero. Each time the count of the counter (20) matches the code produced by the device (12), the counter is incremented. If the counter overflows (i.e., its count has exceeded 2.sup.n -1) within a prescribed interval, then the device (12) is said to be operating properly.