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:
Oct. 13, 2009
Filed:
Apr. 24, 2008
William George John Schofield, North Andover, MA (US);
Lawrence A. Singer, Wenham, MA (US);
William George John Schofield, North Andover, MA (US);
Lawrence A. Singer, Wenham, MA (US);
Analog Devices, Inc., Norwood, MA (US);
Abstract
A system and method are provided for isolating an input without adding significant distortion and without significantly adversely affecting the bandwidth of input circuits. In one embodiment, a single ended signal is substantially cancelled by an arrangement including an input resistance path in parallel with a negative resistance path wherein both paths substantially match in resistance. In another embodiment, a differential signal is substantially cancelled by a pseudo differential arrangement including two independent input resistance paths each in parallel with a corresponding negative resistance path, wherein the resistance paths substantially match the input resistance paths. In yet another embodiment, a differential signal is substantially cancelled by a differential arrangement including two resistance paths wherein a first negative resistance path is coupled between the first differential input and the second differential output and the second negative resistance path is coupled between the second input and the first output. In yet another embodiment, a current controlled current source may provide the negative amplification for the negative resistance path.