Data storage device with closed loop extended park mode during spin down operation

Patent metadata

Field	Value
Publication number	US-11978482-B2
Application number	US-202217577300-A
Country	US
Kind code	B2
Filing date	Jan 17, 2022
Priority date	Jan 17, 2022
Publication date	May 7, 2024
Grant date	May 7, 2024

Abstract

A data storage device has a closed loop extended park mode during spin down operation. A data storage device comprises a spindle motor configured to rotate one or more disks, and one or more processing devices. The one or more processing devices are configured to determine a value of current that is discharged from the spindle motor over time during a spin down of the spindle motor, and control a braking duty cycle for braking the spindle motor during the spin down such that the value of current discharged from the spindle motor over time does not exceed a selected current limit.

First claim

What is claimed is:

1. A data storage device comprising:
a spindle motor configured to rotate one or more disks; and
one or more processing devices configured to:
determine a value of current that is discharged from the spindle motor over time during a spin down of the spindle motor;
control a braking duty cycle for braking the spindle motor during the spin down such that the value of current discharged from the spindle motor over time does not exceed a selected current limit; and
control the braking duty cycle such that the value of current discharged through the spindle motor over time remains at or below a maximum current rating of the spindle motor.

2. A data storage device comprising:
a spindle motor configured to rotate one or more disks; and
one or more processing devices configured to:
determine a value of current that is discharged from the spindle motor over time during a spin down of the spindle motor;
control a braking duty cycle for braking the spindle motor during the spin down such that the value of current discharged from the spindle motor over time does not exceed a selected current limit; and
set the selected current limit at a value below a maximum current rating of the spindle motor.

3. The data storage device of claim 2 , wherein the maximum current rating of the spindle motor is approximately 3 amps, and the one or more processing devices are further configured to set the selected current limit at a value that is less than 3 amps.

4. A data storage comprising:
a spindle motor configured to rotate one or more disks; and
one or more processing devices configured to:
determine a value of current that is discharged from the spindle motor over time during a spin down of the spindle motor; and
control a braking duty cycle for braking the spindle motor during the spin down such that the value of current discharged from the spindle motor over time does not exceed a selected current limit,

wherein the current discharged from the spindle motor is discharged through one or more low-side switches of the spindle motor, and
wherein determining the value of current discharged from the spindle motor comprises determining a value of current through the one or more low-side switches of the spindle motor.

5. The data storage device of claim 4 , wherein the one or more processing devices are further configured to use a feedback loop to set the braking duty cycle, the feedback loop comprising a proportional integral controller configured to modify the braking duty cycle based on feedback of the determined value of current through the one or more low-side switches of the spindle motor, such that the current through the one or more low-side switches remains at or below the selected current limit of the spindle motor.

6. A data storage device comprising:
a spindle motor configured to rotate one or more disks;
a voice coil motor (VCM) that comprises left and right low-side switches; and
one or more processing devices configured to:
determine a value of current that is discharged from the spindle motor over time during a spin down of the spindle motor;
control a braking duty cycle for braking the spindle motor during the spin down such that the value of current discharged from the spindle motor over time does not exceed a selected current limit; and
shunt a portion of the current discharged from the spindle motor during a spin down of the spindle motor through both the left and right low-side switches comprised in the VCM.

7. The data storage device of claim 6 , wherein the one or more processing devices are further configured to load-balance the portion of the current shunted through the left and right low-side switches.

8. A method comprising:
determining, by one or more processing devices, a value of current that is discharged from a spindle motor of a data storage device over time during a spin down of the spindle motor; and
controlling, by the one or more processing devices, a braking duty cycle for braking the spindle motor during the spin down such that the value of current discharged from the spindle motor over time does not exceed a selected current limit; and
shunting a portion of the current discharged from the spindle motor during a spin down of the spindle motor through both left and right low-side switches comprised in a voice coil motor (VCM) of the data storage device.

9. The method of claim 8 , further comprising:
controlling the braking duty cycle such that the value of current discharged through the spindle motor over time remains at or below a maximum current rating of the spindle motor.

10. The method of claim 8 , further comprising
setting the selected current limit at a value below a maximum current rating of the spindle motor.

11. The method of claim 10 , wherein the maximum current rating of the spindle motor is approximately 3 amps, the method further comprising setting the selected current limit at a value that is less than 3 amps.

12. The method of claim 8
wherein the current discharged from the spindle motor is discharged through one or more low-side switches of the spindle motor, and
wherein determining the value of current discharged from the spindle motor comprises determining a value of current through the one or more low-side switches of the spindle motor.

13. The method of claim 12 , further comprising using a feedback loop to set the braking duty cycle, the feedback loop comprising a proportional integral controller configured to modify the braking duty cycle based on feedback of the determined value of current through the one or more low-side switches of the spindle motor, such that the current through the one or more low-side switches remains at or below the selected current limit of the spindle motor.

14. The method of claim 8 , further comprising load-balancing the portion of the current shunted through the left and right low-side switches.

15. One or more processing devices comprising:
means for determining a value of current that is discharged from a spindle motor of a data storage device over time during a spin down of the spindle motor;
means for controlling a braking duty cycle for braking the spindle motor during the spin down such that the value of current discharged from the spindle motor over time does not exceed a selected current limit; and
means for controlling the braking duty cycle such that the value of current discharged through the spindle motor over time remains at or below a maximum current rating of the spindle motor.

16. The one or more processing devices of claim 15 ,
wherein the current discharged from the spindle motor is discharged through one or more low-side switches of the spindle motor, and
wherein determining the value of current discharged from the spindle motor comprises determining a value of current through the one or more low-side switches of the spindle motor.

17. The one or more processing devices of claim 15 , further comprising
means for shunting a portion of the current discharged from the spindle motor during a spin down of the spindle motor through both left and right low-side switches comprised in a voice coil motor (VCM) of the data storage device.

Assignees

• Western Digital Tech Inc

Inventors

• Johnson Brian
• Byoun Jaesoo
• Ikedo Gaku
• Ito Hideaki
• Kagami Naoyuki

Classifications

• G11B19/2063 Primary

  Spindle motor power-down sequences · CPC title

• G11B19/22

  Brakes other than speed-regulating brakes · CPC title

• G11B19/26

  Speed-changing arrangements; Reversing arrangements; Drive-transfer means therefor · CPC title

• G11B19/28

  Speed controlling, regulating, or indicating (G11B19/24 takes precedence) · CPC title