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:
Jul. 28, 2009
Filed:
Mar. 04, 2008
Thomas L. Botker, Andover, MA (US);
Benjamin A. Douts, Tewksbury, MA (US);
Thomas L. Botker, Andover, MA (US);
Benjamin A. Douts, Tewksbury, MA (US);
Analog Devices, Inc., Norwood, MA (US);
Abstract
A current-mode instrumentation amplifier (IA) error reduction circuit and method employs a current-mode IA topology and an auto-zero circuit. The IA receives a differential voltage (VINP−VINN) and produces differential DC currents (I, I) in response, which are summed to produce the amplifier's output current. Ideally, when VINP=VINN, Iand Iwill be equal; however, due to mismatches an error component Iwill be present such that I=I±I. The auto-zero circuit is employed to reduce the magnitude of I. In operation, in an 'auto-zero mode', VINP and VINN are connected together and the auto-zero circuit operates to make I=I; a voltage needed to effect this is stored. Then, in 'normal mode', VINP and VINN are disconnected from each other and the IA is placed in the signal path, with the stored voltage acting to keep the magnitude of Ilow.