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:
Apr. 30, 2002
Filed:
Mar. 15, 2001
Bertram J. White, Irvine, CA (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A circuit for providing commutation control signals to a commutator for a polyphase brushless dc motor in a mass data storage device includes an accumulator ( ) to accumulate a digital count that is proportional or related to a phase difference between the commutation control signals and a motor bemf. A digital variable frequency oscillator ( ) generates an oscillator output signal of frequency proportional to the digital count to reset the accumulator ( ) after a predetermined time determined by the frequency. The circuit may also include a digital filter ( ) between the digital accumulator ( ) and the digital variable frequency oscillator ( ) to generate a magnitude signal (DRC) of magnitude proportional to the accumulated count for delivery to the variable frequency oscillator ( ) to control the frequency thereof.