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:
Mar. 27, 2007
Filed:
May. 20, 2005
David A. Gammie, Tucson, AZ (US);
Sergey V. Alenin, Tucson, AZ (US);
David A. Gammie, Tucson, AZ (US);
Sergey V. Alenin, Tucson, AZ (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
An amplifier circuit includes first (A) and second (B) operational amplifiers connected in a generally parallel configuration, each with inputs coupled through the same pair of matched input resistors which receive a differential input signal that may have both a positive and negative common mode range. An offset adjustment amplifier () receives a differential error signal representative of the difference between offset voltages of the first and second operational amplifiers and generates offset adjustment signals that are applied to input stages of the first and second operational amplifiers to adjust their respective offset voltages so as to equalize them. With the offset voltages equalized, the first and second operational amplifiers operate seamlessly as a common mode component of the differential input signal undergoes a transition from its positive to its negative range, so as to avoid inaccuracies and abrupt changes in an output voltage during the transition, the output voltage being produced in response to outputs of both first and second operational amplifiers.