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:
Sep. 22, 2009
Filed:
Apr. 03, 2007
Dimitar T. Trifonov, Vail, AZ (US);
Marco A. Gardner, Tucson, AZ (US);
Dimitar T. Trifonov, Vail, AZ (US);
Marco A. Gardner, Tucson, AZ (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A differential amplifier includes a differential input pair (A) coupled to a folded cascode stage (B) and a common mode feedback circuit () including a tracking circuit (A) coupled to first (Vout) and second (Vout) outputs of the folded cascode stage (B). The first and second outputs are coupled to first terminals of first (A) and second (B) tracking capacitors which have second terminals on which a first common mode output signal (V) is produced and also are coupled to first terminals of third (A) and fourth (B) tracking capacitors, respectively, which have second terminals on which a second common mode output signal (V) is produced. The first and third tracking capacitors are discharged by first (A) and second (B) switches that directly couple the first and second outputs to first and second inputs of a common mode feedback amplifier (). A desired common mode output voltage (V) is applied to a third input of the common mode feedback amplifier. The switches are opened to cause the first and second common mode output voltages to be generated, causing a common mode feedback control signal (V) to be generated for biasing the folded cascode stage.