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:
Apr. 15, 1997
Filed:
Sep. 29, 1994
Charles E Goetzinger, Bloomington, MN (US);
David E Tetzlaff, Minnetonka, MN (US);
Rosemount Inc., Eden Prairie, MN (US);
Abstract
A calibrating system calibrates an analog-to-digital converter which has an integrator and first and second reference current sources. A quantity of charge is accumulated in the integrator. The quantity of charge is removed from the integrator by applying the first and second reference currents to the integrator for first and second time periods until the accumulated charge reaches a threshold level. The quantity of charge is reaccumulated in the integrator and again removed by applying the first and second reference currents for third and fourth time periods wherein the first and second time periods are different from the third and fourth time periods. The relative magnitude of the first and second reference currents is determined based on the first, second, third and fourth time periods.