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. 26, 2000
Filed:
Mar. 26, 1999
John Kardash, Ione, CA (US);
Quantum Corporation, Milpitas, CA (US);
Abstract
A motor driver circuit for a three-phase wound disk drive spindle motor having multiple phase coils and corresponding coil drivers, and commutation phase generation means responsive to BEMF voltage zero crossings of the phase coils for generating commutation cycle control signals for the motor phases. The motor driver circuit comprises: a sensor for sensing a voltage level of a coil; a timing signal generator for generating successive state control signals in response to said commutation timing signals, the state control signals corresponding to successive BEMF voltage zero crossings of the phase coils, wherein a pulse generation interval is defined by a pair of successive state control signals; and a pulse generator coupled to the sensor and responsive to the state control signals, for generating a train of drive control pulses to the corresponding coil driver during each pulse generation interval for controlling current flow in the coil in response to sensed coil current levels to form a desired current waveform therein, each pulse including: (1) an ON period wherein said coil driver applies a drive current to the coil, and (2) an fixed OFF period wherein said coil driver cuts of the drive current to the coil for a fixed time interval.