초록 ▼

A production line spindle control circuit is disclosed for use in manufacturing a disk drive. The production line spindle control circuit generates sinusoidal driving currents applied to a spindle motor of the disk drive, and processes a back EMF signal generated by the spindle motor in order to con

A production line spindle control circuit is disclosed for use in manufacturing a disk drive. The production line spindle control circuit generates sinusoidal driving currents applied to a spindle motor of the disk drive, and processes a back EMF signal generated by the spindle motor in order to control a commutation sequence as well as the angular velocity of the spindle motor. The production line spindle control circuit is attached to the spindle motor during a manufacturing procedure, such as servo writing, and detached from the spindle motor after the manufacturing procedure.

대표청구항 ▼

1. A production line spindle control circuit for manufacturing a disk drive, the disk drive comprising a disk, a head actuated radially over the disk, and a multi-phase spindle motor comprising a plurality of windings for rotating the disk, the production line spindle control circuit comprising:(a)

1. A production line spindle control circuit for manufacturing a disk drive, the disk drive comprising a disk, a head actuated radially over the disk, and a multi-phase spindle motor comprising a plurality of windings for rotating the disk, the production line spindle control circuit comprising:(a) a sinusoidal driver for generating a plurality of sinusoidal driving currents;(b) an interface for:applying the sinusoidal driving currents to the spindle motor windings in order to rotate the spindle motor; andreceiving a back EMF signal representing a back EMF voltage across at least one of the spindle motor windings; and(c) a commutation controller for:applying the sinusoidal driving currents to the spindle motor windings in a commutation sequence in response to the back EMF signal; andcontrolling an angular velocity of the spindle motor in response to the back EMF signal,wherein the interface for attaching to the spindle motor during a manufacturing procedure and for detaching from the spindle motor after the manufacturing procedure. 2. The production line spindle control circuit as recited in claim 1, wherein the back EMF signal is converted into a square wave having edges defined relative to when the back EMF voltage crosses a predetermined threshold. 3. The production line spindle control circuit as recited in claim 2, wherein the commutation controller changes a state of the commutation sequence relative to the edges of the square wave. 4. The production line spindle control circuit as recited in claim 2, wherein a frequency of the square wave represents the angular velocity of the spindle motor. 5. The production line spindle control circuit as recited in claim 1, wherein the sinusoidal driver comprises a linear driver for generating substantially linear sinusoidal driving currents. 6. The production line spindle control circuit as recited in claim 1, wherein the sinusoidal driver comprises a pulse width modulating driver for pulse width modulating the sinusoidal driving currents. 7. The production line spindle control circuit as recited in claim 1, wherein the production line spindle control circuit for use by a servo writer for servo writing embedded servo patterns onto the disk during the manufacturing procedure. 8. A method of manufacturing a disk drive, the disk drive comprising a disk, a head actuated radially over the disk, and a multi-phase spindle motor comprising a plurality of windings for rotating the disk, the method of manufacturing a disk drive comprising the steps of:(a) attaching a production line spindle control circuit to the spindle motor during a manufacturing procedure, the production line spindle control circuit for generating a plurality of sinusoidal driving currents;(b) the production line spindle control circuit receiving a back EMF signal from the spindle motor, the back EMF signal representing a back EMF voltage across at least one of the spindle motor windings;(c) the production line spindle control circuit applying the sinusoidal driving currents to the spindle motor windings in a commutation sequence in response to the back EMF signal;(d) the production line spindle control circuit controlling an angular velocity of the spindle motor in response to the back EMF signal; and(e) detaching the production line spindle control circuit from the spindle motor after the manufacturing procedure. 9. The method of manufacturing a disk drive as recited in claim 8, further comprising the step of converting the back EMF signal into a square wave having edges defined relative to when the back EMF voltage crosses a predetermined threshold. 10. The method of manufacturing a disk drive as recited in claim 9, further comprising the step of changing the state of the commutation sequence relative to the edges of the square wave. 11. The method of manufacturing a disk drive as recited in claim 9, wherein a frequency of the square wave represents the angular velocity of the spindle motor. 12. The method of manufact uring a disk drive as recited in claim 8, wherein the sinusoidal driving currents are substantially linear. 13. The method of manufacturing a disk drive as recited in claim 8, wherein the production line spindle control circuit pulse width modulates the sinusoidal driving currents. 14. The method of manufacturing a disk drive as recited in claim 8, further comprising the step of servo writing embedded servo patterns onto the disk using the production line spindle control circuit during the manufacturing procedure.