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:
Jun. 13, 1995
Filed:
Jul. 01, 1994
Applicant:
Inventor:
Daniel B Carson, Bothell, WA (US);
Assignee:
Fluke Corporation, Everett, WA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01R / ;
U.S. Cl.
CPC ...
330-2 ; 330 69 ; 330258 ; 3241 / ;
Abstract
Common mode error correction for differential amplifiers involves accurately measuring both the input and output of an amplifier using a low-leakage measurement path, and calculating common-mode gain. Two measurements are made at each node by appying two different common-mode voltages. Subtracting one set of measurements from the other eliminates voltage offset errors, and leaves a common-mode error term for gain calculation. The common-mode gain factor is stored, and thereafter, common mode error may be subtracted from measurements made by the differential amplifier.