Disk drive employing commutation phase modulation and current modulation of a spindle motor
AssigneeWestern Digital Technologies, Inc.
InventorsRaffi Codilian, Timothy A. Ferris
Life of this patent
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Abstract
A disk drive is disclosed comprising a spindle motor comprising a plurality of windings for rotating a disk. The spindle motor is rotated by commutating the windings over a plurality of commutation states, wherein audible noise generated by the disk drive is reduced by phase modulating the commutation interval. Further audible noise reduction is achieved by modulating a current applied to the windings which substantially reduces discontinuities in the torque output of the spindle motor caused by phase modulation of the commutation intervals.
Claims12
A disk drive comprising:
- (a) a disk;
- (b) a head actuated over the disk;
- (c) a spindle motor for generating a torque output to rotate the disk, the spindle motor comprising a plurality of windings;
- (d) a power driver comprising a plurality of commutation switches for selectively energizing the windings;
- (e) a commutation sequencer for controlling the commutation switches to configure the windings into a plurality of commutation states over a plurality of commutation intervals;
- (f) a phase modulator for phase modulating the commutation intervals;
- and
- (g) a current modulator for controlling a current applied to the windings in each of the commutation states to substantially reduce discontinuities in the torque output of the spindle motor caused by the phase modulator.
A method of operating a disk drive, the disk drive comprising, a disk, a head actuated over the disk, and a spindle motor for generating a torque output to rotate the disk, the spindle motor comprising a plurality of windings, the method comprising the steps of:
- (a) selectively energizing the windings based on a plurality of commutation states over a plurality of commutation intervals;
- (b) modulating a phase of the commutation intervals;
- and
- (c) modulating a current applied to the windings in each of the commutation states to substantially reduce discontinuities in the torque output of the spindle motor caused by modulating the phase of the commutation intervals.
Dependencies are inferred from the claim text.