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:
May. 28, 2002
Filed:
Jun. 28, 2000
Karl H. Jacobs, Torrington, CT (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
An operational amplifier trim circuit architecture that compensates for fabrication process and temperature drift mismatches reflected to the input as input offset voltage errors without additional temperature compensation circuitry. The operational amplifier includes a first input signal and second input signal applied to an input circuit stage. The input circuit stage amplifies the first input signal differentially with respect to the second input stage and generates a differential current which in turn is applied to a first current path and a second current path. The first current path and second current path have well-matched trim circuits. The first current trim applies a trim current to the first current path, and the second current trim applies a trim current to the second current path. The trim current includes an offset current that is well-matched on both the first current trim path and the second current trim path and, in addition, may have a trim offset current that is present on the first trim current and not on the second trim current or vice versa, depending on the actual mismatch requiring correction on the particular device being trimmed. Thus, since both the first current path and the second current path see identical offset currents that are influenced by temperature variations in the same manner, the input offset voltage of the operational amplifier will have minimum drift over temperature variations.