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:
Jan. 23, 2007
Filed:
Jun. 15, 2005
Thomas L. Botker, Tucson, AZ (US);
Thomas L. Botker, Tucson, AZ (US);
Analog Devices, Inc., Norwood, MA (US);
Abstract
A current-mode instrumentation amplifier (IA) includes first and second buffer amplifiers which receive a differential voltage (VINP−VINN) and provide output voltages at respective output nodes; a resistance Ris connected between the nodes and conducts a current Ithat varies with VINP−VINN. In one embodiment, each amplifier includes a transistor connected in series with Rwhich conducts current I; these currents are coupled to the input and output terminals of a current mirror, preferably via respective virtual ground nodes such that the IA requires only one current mirror, to produce the IA's output voltage. To minimize DC mismatch errors, the IA is chopper-stabilized, with the buffer amplifiers and signal current paths chopped using a two-phase chopping cycle.