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. 10, 2007
Filed:
Dec. 16, 1999
Tan Du, Plano, TX (US);
John K. Rote, Addison, TX (US);
Tan Du, Plano, TX (US);
John K. Rote, Addison, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A circuit () and method are presented to accurately determine a BEMF voltage of a VCM coil () after termination of a driving current in a first current direction in the coil (). The circuit includes a circuit for activating selected VCM coil driver transistors () to apply a current to the coil () in a direction opposite the first current direction to generate a magnetic field to oppose eddy currents established in structures adjacent the coil () by the driving current. The time that the eddy current opposing current may be applied may be determined, for example, by determining a magnitude of the original current command, a time that the coil spends in flyback, or a magnitude of the original driving current, and adjusting the time of application of the eddy current opposing current accordingly.