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. 28, 1981
Filed:
Apr. 19, 1979
Applicant:
Inventor:
W David Pace, Tempe, AZ (US);
Assignee:
Motorola, Inc., Schaumburg, IL (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03K / ;
U.S. Cl.
CPC ...
3403 / ; 307350 ; 328146 ; 3403 / ; 3403 / ; 3403 / ;
Abstract
In a dual-slope A/D converter employing hysteresis, a reference voltage circuit sets the threshold of the comparator at three distinct levels in response to a ramp control signal and the comparator output. As a reference capacitor ramps through a threshold voltage, the comparator output shifts the threshold with positive feedback (hysteresis) to provide noise immunity. The ramp control signal then shifts the threshold back to its original level cancelling the hysteresis provided at the first comparator trip point. Thus, the comparator switches at the same voltage for both slopes eliminating offset error.