Dual spindle motors and dual spindle motor control for data storage

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 comprising a back electromotive force (BEMF) comparator detection circuitry configured to detect BEMF voltages generated by the first spindle motor and by the second spindle motor;
• wherein the motor controller is configured to:
• control speeds of the first spindle motor and the second spindle motor based on the detected BEMF voltages, and
• drive, based on sine wave current profiles, the first spindle motor and the second spindle motor.

A data storage device comprising:

• a first spindle motor configured to rotate one or more disks in a first stack of disks, wherein the first spindle motor has a first three-phase winding topology comprising first windings and a first back electromotive force (BEMF) voltage is generated in each of the first windings,
• a second spindle motor configured to rotate one or more disks in a second stack of disks, wherein the second spindle motor has a second three-phase winding topology comprising second windings and a second BEMF voltage is generated in each of the second windings;
• and
• a BEMF comparator detection circuitry configured to be coupled to both first and second spindle motors to detect the first and second BEMF voltages;
• wherein the BEMF comparator detection circuitry is configured on a power large scale integrated circuit (PLSI) and is further configured to be switchably coupled to the first and second spindle motors.

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;
• switchably coupling the BEMF comparator detection circuitry to a phase A BEMF voltage of the first spindle motor or to a phase A BEMF voltage of the second spindle motor;
• switchably coupling the BEMF comparator detection circuitry to a phase B BEMF voltage of the first spindle motor or to a phase B BEMF voltage of the second spindle motor;
• and
• switchably coupling the BEMF comparator detection circuitry to a phase C BEMF voltage of the first spindle motor or to a phase C BEMF voltage of the second spindle motor.