Western Digital Technologies, Inc.

Wenli Yang

Ashok K Desai

Jianghong Ding

Robert P Ryan

Jenghung Chen

Charles J Calaway

William T Stoll

Brandon P Smith

Philip Tin Yue Ng

Taylor Watanabe

Angel Yu

Jinsik Kim

An apparatus includes: a media; a head assembly over the media; a head actuation motor coupled to the head assembly; control circuitry, coupled to the head actuation motor, configured to position the head assembly; and a head loading ramp, adjacent to the media; wherein: the control circuitry is further configured to: generate a seek count; and park the head assembly, off of the media, on the head loading ramp, controlling a speed of the head actuation motor based on the seek count.

Electronic system with unload management mechanism and method of operation thereof

A disk drive is disclosed comprising a head actuated over a disk, and a spindle motor operable to rotate the disk. The disk drive comprises control circuitry configured to a rotation speed of the spindle motor, generate a gain as a function of the measured rotation speed, wherein the function comprises a polynomial having a degree greater than one, and spin-up the spindle motor based on the gain.

Disk drive with improved spin-up control

A disk drive is disclosed comprising a head actuated over a disk, a spindle motor for rotating the disk, and a spindle motor control system comprising a servo compensator operable to generate a control signal applied to the spindle motor, the servo compensator comprising a programmable gain term (PGT). The disk is spun at a first speed RPMusing a first value PGTselected for the PGT, and the disk is spun at a second speed RPMusing a second value PGTselected for the PGT, wherein the second value PGTis generated in response to the first value PGTscaled by a function of a ratio of RPMto RPM

Disk drive adjusting gain of spindle motor compensator based on a ratio of spin speeds

A disk drive is disclosed comprising a head actuated over a disk, a spindle motor operable to rotate the disk, and control circuitry comprising a speed control loop operable to control a rotation speed of the disk. A rotation speed of the disk is measured, and a speed error is generated in response to the measured rotation speed. The speed error is processed with a compensator to generate a control signal, a disturbance is injected into the control signal to generate a modified control signal, and the modified control signal is applied to the spindle motor. An amplitude of the disturbance is ramped, and after ramping the amplitude of the disturbance, an open-loop gain of the speed control loop is estimated at a frequency of the disturbance, and at least one parameter of the compensator is adjusted in response to the estimated open-loop gain.

Disk drive tuning speed control loop for a spindle motor

A disk drive is disclosed comprising a head actuated over a disk, and a spindle motor for rotating the disk, the spindle motor comprising a plurality of windings. During a spin-up operation a sinusoidal driving voltage is applied to each winding of the spindle motor. A back electromotive force (BEMF) voltage generated by at least one of the windings is measured, and a rotation speed of the spindle motor is measured. The sinusoidal driving voltage is adjusted in order to optimize a lead angle relative to the rotation speed, wherein the lead angle represents a degree the sinusoidal driving voltage leads the BEMF voltage.

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Los Angeles, CA, United States of America

Wenli Yang