Dual spindle motors and dual spindle motor control for data storage

Patent metadata

Field	Value
Publication number	US-11823710-B2
Application number	US-202217679219-A
Country	US
Kind code	B2
Filing date	Feb 24, 2022
Priority date	Feb 24, 2022
Publication date	Nov 21, 2023
Grant date	Nov 21, 2023

Abstract

Various illustrative aspects are directed to a data storage device comprising a first spindle motor configured to rotate one or more disks in a first stack of disks, a second spindle motor configured to rotate one or more disks in a second stack of disks, and one or more processing devices configured to detect back electromotive force (BEMF) voltages generated by the first spindle motor and the second spindle motor. In other aspects the one or more processing devices can control speeds of the first spindle motor and the second spindle motor based on the detected BEMF voltages.

First claim

What is claimed is:

1. A data storage device comprising:
a first spindle motor configured to rotate one or more disks in a first stack of disks;
a second spindle motor configured to rotate one or more disks in a second stack of disks; and
one or more processing devices comprising a motor controller, wherein
the motor controller has back electromotive force (BEMF) comparator detection circuitry configured to detect BEMF voltages generated by the first spindle motor and the second spindle motor, and
the motor controller is configured to control speeds of the first spindle motor and the second spindle motor based on the detected BEMF voltages, wherein

the BEMF comparator detection circuitry comprises a first BEMF comparator and a second BEMF comparator;
the first BEMF comparator is configured to be coupled to one phase of the BEMF voltages of the first spindle motor; and
the second BEMF comparator is configured to be coupled to the same one phase of the BEMF voltages of the second spindle motor.

2. The data storage device of claim 1 , wherein:
the BEMF comparator detection circuitry is configured on one power large scale integrated circuit (PLSI) to detect the BEMF voltages generated by both the first spindle motor and the second spindle motor.

3. The data storage device of claim 2 , wherein:
the first BEMF comparator is configured to be coupled to a center tap voltage of the first spindle motor; and
the second BEMF comparator is configured to be coupled to a center tap voltage of the second spindle motor.

4. The data storage device of claim 3 , wherein:
the motor controller further comprises a motor speed controller;
the first BEMF comparator is configured to output a phase A BEMF voltage of the first spindle motor on a first BEMF output of the PLSI that is configured to be coupled to the motor speed controller; and
the second BEMF comparator is configured to output a phase A BEMF voltage of the second spindle motor on a second BEMF output of the PLSI that is configured to be coupled to the motor speed controller.

5. The data storage device of claim 4 , wherein the motor speed controller is configured on a system on a chip (SoC).

6. A data storage device comprising:
a first spindle motor configured to rotate one or more disks in a first stack of disks;
a second spindle motor configured to rotate one or more disks in a second stack of disks; and
one or more processing devices comprising a motor controller, wherein:
the motor controller has back electromotive force (BEMF) comparator detection circuitry configured to detect BEMF voltages generated by the first spindle motor and the second spindle motor, and
the motor controller is configured to control speeds of the first spindle motor and the second spindle motor based on the detected BEMF voltages, wherein:

the BEMF comparator detection circuitry comprises a first BEMF comparator, a second BEMF comparator and a third BEMF comparator;
the first BEMF comparator is configured to be switchably coupled to a phase A BEMF voltage of the first spindle motor or to a phase A BEMF voltage of the second spindle motor;
the second BEMF comparator is configured to be switchably coupled to a phase B BEMF voltage of the first spindle motor or to a phase B BEMF voltage of the second spindle motor; and
the third BEMF comparator is configured to be switchably coupled to a phase C BEMF voltage of the first spindle motor or to a phase C BEMF voltage of the second spindle motor.

7. The data storage device of claim 6 , wherein:
the first BEMF comparator is configured to be switchably coupled to a center tap voltage of the first spindle motor or to a center tap voltage of the second spindle motor;
the second BEMF comparator is configured to be switchably coupled to the center tap voltage of the first spindle motor or to the center tap voltage of the second spindle motor; and
the third BEMF comparator is configured to be switchably coupled to the center tap voltage of the first spindle motor or to the center tap voltage of the second spindle motor.

8. The data storage device of claim 7 , wherein:
the motor controller further comprises a motor speed controller;
the first BEMF comparator is configured to be switchably coupled to a first BEMF output that is configured to output the phase A BEMF voltage of the first spindle motor to the motor speed controller, or to a second BEMF output that is configured to output the phase A BEMF voltage of the second spindle motor to the motor speed controller;
the second BEMF comparator is configured to be switchably coupled to the first BEMF output to output the phase B BMF voltage of the first spindle motor to the motor speed controller, or to the second BEMF output to output the phase B BMF voltage of the second spindle motor to the motor speed controller; and
the third BEMF comparator is configured to be switchably coupled to the first BEMF output to output the phase C BMF voltage of the first spindle motor to the motor speed controller, or to the second BEMF output to output the phase C BMF voltage of the second spindle motor to the motor speed controller.

9. A data storage device comprising:
a first spindle motor configured to rotate one or more disks in a first stack of disks;
a second spindle motor configured to rotate one or more disks in a second stack of disks; and
one or more processing devices comprising a motor controller, wherein:
the motor controller has back electromotive force (BEMF) comparator detection circuitry configured to detect BEMF voltages generated by the first spindle motor and the second spindle motor, and
the motor controller is configured to control speeds of the first spindle motor and the second spindle motor based on the detected BEMF voltages, wherein:

the motor controller further comprises a sine wave lookup table configured to create sine wave current profiles for driving the first spindle motor and the second spindle motor;
the sine wave lookup table is configured to be shared by the first spindle motor and the second spindle motor; and
the sine wave lookup table comprises a first index configured to index the sine wave current profile for driving the first spindle motor to the sine wave lookup table, and a second index configured to index the sine wave current profile for driving the second spindle motor to the sine wave lookup table.

10. The data storage device of claim 9 , wherein the the BEMF comparator detection circuitry and the sine wave look up table are configured on one power large scale integrated circuit (PLSI).

11. A method comprising:
rotating, by a first spindle motor, one or more disks in a first stack of disks;
rotating, by a second spindle motor, one or more disks in a second stack of disks;
detecting, by one or more processing devices comprising a motor controller having back electromotive force (BEMF) comparator detection circuitry, BEMF voltages generated by the first spindle motor and by the second spindle motor;
controlling, by the one or more processing devices, speeds of the first spindle motor and the second spindle motor based on the detected BEMF voltages;
coupling a first BEMF comparator of the BEMF comparator detection circuitry to a phase A BEMF voltage of the first spindle motor; and
coupling a second BEMF comparator of the BEMF comparator detection circuitry to a phase A BEMF voltage of the second spindle motor.

12. The method of claim 11 , further comprising:
providing, in the motor controller, the BEMF comparator detection circuitry on one power large scale integrated circuit (PLSI) to detect the BEMF voltages generated by both the first spindle motor and the second spindle motor.

Assignees

• Western Digital Tech Inc

Inventors

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

Classifications

• G11B19/28 Primary

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

• G11B25/043 Primary

  using rotating discs · CPC title

• H02K16/00

  Machines with more than one rotor or stator {(machines for transmitting mechanical power from a driving shaft to a driven shaft and comprising structurally interrelated motor and generator parts H02K51/00; permanent magnet machines with multiple rotors or stators relatively rotated for vectorially combining the excitation fields or the armature voltages H02K21/029)} · CPC title

• G11B19/2081

  emergency power-down · CPC title

• G11B2220/2516

  Hard disks · CPC title