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. 17, 2001
Filed:
Sep. 13, 1996
Kevin L. Brown, Orlando, FL (US);
Lockheed Martin Corporation, Bethesda, MD (US);
Abstract
A multiplexer selects multiple input signals to produce an output in which the distortion associated with switching is minimized. Selection of the multiple input signals is performed within a multiplexing operational amplifier. The operational amplifier includes differential amplifiers that receive the respective input signals at their respective noninverting nodes. The differential amplifiers are connected to a feedback signal at their respective inverting nodes. The input signals are selected for output by turning on selection switches within the operational amplifier, causing the respective differential amplifiers to be selected. This minimizes non-linearities in the output due to capacitive coupling and eliminates unwanted resistive effects without requiring complicated circuitry. The selection switches may include complementary back-to-back MOSFETs, or alternatively, same-channel MOSFETs connected in series to cancel capacitive coupling and switch feedthrough within the multiplexing op-amp.