Data storage device optimizing spindle motor power when transitioning into a power failure mode

• US 9,761,266 B2
• Filed: 01/04/2016
• Issued: 09/12/2017
• Est. Priority Date: 12/23/2014
• Status: Active Grant

• Current Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Original Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Inventors: Nicholls, Michael T.
• Primary Examiner(s): Agustin, Peter Vincent
• Application Number:
  US14/987,581
• Publication Number:
  US 20160180877A1
• Time in Patent Office: 617 Days
• Field of Search: None
• CPC Class Codes: G11B 19/20 Driving; Starting; Stopping; Control thereof
• CPC Class Codes: G11B 19/2081 emergency power-down
• CPC Class Codes: G11B 21/12 Raising and lowering; Back-spacing or forward-spacing along track; Returning to starting position otherwise than during transducing operation

Abstract

A data storage device is disclosed comprising a head actuated over a disk, and a spindle motor configured to rotate the disk, wherein the spindle motor comprises a plurality of windings. The windings of the spindle motor are commutated based on a commutation sequence while applying a driving voltage to each winding, wherein the driving voltage comprises an operating polarity during normal operation. When a supply voltage falls below a threshold while the spindle motor is rotating the disk, the spindle motor is configured into a power generator by at least reversing the polarity of the driving voltage for an interval and then reversing the polarity of the driving voltage back to the operating polarity.

Claims

1. A data storage device comprising:

a disk;

a spindle motor configured to rotate the disk, wherein the spindle motor comprises a plurality of windings;

a head actuated over the disk; and

control circuitry powered by a supply voltage, the control circuitry configured to;

commutate the windings based on a commutation sequence while applying a driving voltage to each winding, wherein the driving voltage comprises an operating polarity during normal operation; and

when the supply voltage falls below a threshold while the spindle motor is rotating the disk, configure the spindle motor into a power generator by at least reversing the polarity of the driving voltage for an interval and then reversing the polarity of the driving voltage back to the operating polarity.

2. The data storage device as recited in claim 1, wherein after reversing the polarity of the driving voltage back to the operating polarity the control circuitry is further configured to incrementally step increase an amplitude of the driving voltage by at least one step.

3. The data storage device as recited in claim 1, wherein reversing the polarity of the driving voltage back to the operating polarity comprises configuring an amplitude of the driving voltage to substantially equal a back electromotive force (BEMF) voltage across each winding.

4. A method of operating a data storage device, the method comprising:

commutating windings of a spindle motor configured to rotate a disk based on a commutation sequence while applying a driving voltage to each winding, wherein the driving voltage comprises an operating polarity during normal operation; and

when a supply voltage falls below a threshold while the spindle motor is rotating the disk, configuring the spindle motor into a power generator by at least reversing the polarity of the driving voltage for an interval and then reversing the polarity of the driving voltage back to the operating polarity.

5. The method as recited in claim 4, wherein after reversing the polarity of the driving voltage back to the operating polarity the method further comprises incrementally step increasing an amplitude of the driving voltage by at least one step.

6. The method as recited in claim 4, wherein reversing the polarity of the driving voltage back to the operating polarity comprises configuring an amplitude of the driving voltage to substantially equal a back electromotive force (BEMF) voltage across each winding.

7. A controller for use in a data storage device comprising a disk, a spindle motor configured to rotate the disk, wherein the spindle motor comprises a plurality of windings, and a head actuated over the disk,

the controller comprising control circuitry powered by a supply voltage, the control circuitry configured to:

commutate the windings based on a commutation sequence while applying a driving voltage to each winding, wherein the driving voltage comprises an operating polarity during normal operation; and

when the supply voltage falls below a threshold while the spindle motor is rotating the disk, configure the spindle motor into a power generator by at least reversing the polarity of the driving voltage for an interval and then reversing the polarity of the driving voltage back to the operating polarity.

8. The controller as recited in claim 7, wherein after reversing the polarity of the driving voltage back to the operating polarity the control circuitry is further configured to incrementally step increase an amplitude of the driving voltage by at least one step.

9. The controller as recited in claim 7, wherein reversing the polarity of the driving voltage back to the operating polarity comprises configuring an amplitude of the driving voltage to substantially equal a back electromotive force (BEMF) voltage across each winding.