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. 20, 2010
Filed:
Nov. 30, 2004
Robert W Walden, Bethlehem, PA (US);
Robert W Walden, Bethlehem, PA (US);
Agere Systems Inc., Allentown, PA (US);
Abstract
A method and apparatus for selecting and mixing electronic signals. The circuit has an operational amplifier and two or more ganged, tapped-resistors in which the tap divides the resistance into a first and a second resistance. The tapped-resistors are connected so that either the first or the second resistance provides the effective input resistance for that signal at the operational amplifier. The second resistance of one of the tapped-resistors provides the output resistance for all signals at operational amplifier. As the tapped resistors are equivalent and their taps ganged, when the signals are mixed, those signals whose effective input resistance at the operational amplifier is selected to be the second resistance have unit gain, while those signals whose effective input resistance at the operational amplifier is selected to be the first resistance have a gain equal to the second resistance divide by the first resistance.