Disk drive calibrating preamp for servo sectors and data sectors
AssigneeWestern Digital Technologies, Inc.
InventorsKwok Foong Haw, Jame Show Leiong Hii
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Abstract
A disk drive is disclosed comprising a head actuated over a disk including a plurality of tracks defined by servo sectors, wherein each track comprises a plurality of data sectors. The disk drive further comprises a preamp circuit operable to amplify a read signal emanating from the head to generate a pre-amplified read signal. A first gain setting of the preamp circuit is calibrated in response to a plurality of the servo sectors, and the first gain setting is adjusted in response to a plurality of the data sectors.
Claims16
A disk drive comprising:
- a disk comprising a plurality of tracks defined by servo sectors, wherein each track comprises a plurality of data sectors;
- a head actuated over the disk;
- a preamp circuit operable to amplify a read signal emanating from the head to generate a pre-amplified read signal;
- and
- control circuitry comprising a variable gain amplifier (VGA) operable to amplify the pre-amplified read signal to generate an amplified read signal, the control circuitry operable to:
- calibrate a first gain setting of the preamp circuit in response to a plurality of the servo sectors;
- adjust the first gain setting in response to a plurality of the data sectors;
- adjust a second gain setting of the VGA in order to adjust an amplitude of the amplified read signal based on a target response;
- calibrate the first gain setting of the preamp circuit in response to the second gain setting;
- wherein:
- the control circuitry is operable to calibrate the first gain setting in response to the servo sectors by:
- increasing the first gain setting when the second gain setting is greater than a servo maximum threshold;
- and
- decreasing the first gain setting when the second gain setting is less than a servo minimum threshold,
- the control circuitry is operable to adjust the first gain setting in response to the data sectors by:
- increasing the first gain setting when the second gain setting is greater than a data maximum threshold;
- and
- decreasing the first gain setting when the second gain setting is less than a data minimum threshold;
- and
- a range defined by the data maximum threshold and the data minimum threshold is wider than a range defined by the servo maximum threshold and the servo minimum threshold.
A method of operating a disk drive comprising a disk including a plurality of tracks defined by servo sectors, wherein each track comprises a plurality of data sectors, a head actuated over the disk, a preamp circuit operable to amplify a read signal emanating from the head to generate a pre-amplified read signal, and a variable gain amplifier (VGA) operable to amplify the pre-amplified read signal to generate an amplified read signal, the method comprising:
- calibrating a first gain setting of the preamp circuit in response to a plurality of the servo sectors;
- adjusting the first gain setting in response to a plurality of the data sectors;
- adjusting a second gain setting of the VGA in order to adjust an amplitude of the amplified read signal based on a target response;
- and
- calibrating the first gain setting of the preamp circuit in response to the second gain setting,
- wherein:
- calibrating the first gain setting in response to the servo sectors comprises:
- increasing the first gain setting when the second gain setting is greater than a servo maximum threshold;
- and
- decreasing the first gain setting when the second gain setting is less than a servo minimum threshold;
- adjusting the first gain setting in response to the data sectors comprises:
- increasing the first gain setting when the second gain setting is greater than a data maximum threshold;
- and
- decreasing the first gain setting when the second gain setting is less than a data minimum threshold;
- and
- a range defined by the data maximum threshold and the data minimum threshold is wider than a range defined by the servo maximum threshold and the servo minimum threshold.
A disk drive comprising:
- a disk comprising a plurality of tracks defined by servo sectors, wherein each track comprises a plurality of data sectors;
- a head actuated over the disk;
- a preamp circuit operable to amplify a read signal emanating from the head to generate a pre-amplified read signal;
- and
- control circuitry comprising a variable gain amplifier (VGA) operable to amplify the pre-amplified read signal to generate an amplified read signal, and a cut-off filter for filtering the amplified read signal output by the VGA when reading the servo sectors, the control circuitry operable to:
- calibrate a first gain setting of the preamp circuit in response to a plurality of the servo sectors;
- adjust the first gain setting in response to a plurality of the data sectors;
- adjust a second gain setting of the VGA in order to adjust an amplitude of the amplified read signal based on a target response;
- and
- after adjusting the first gain setting in response to the data sectors, adjust the cut-off filter when the second gain setting while reading the servo sectors is outside a range.
A method of operating a disk drive, the disk drive comprising a disk comprising a plurality of tracks defined by servo sectors, wherein each track comprises a plurality of data sectors, a head actuated over the disk, a preamp circuit operable to amplify a read signal emanating from the head to generate a pre-amplified read signal, and control circuitry comprising a variable gain amplifier (VGA) operable to amplify the pre-amplified read signal to generate an amplified read signal, and a cut-off filter for filtering the amplified read signal output by the VGA when reading the servo sectors, the method comprising:
- calibrating a first gain setting of the preamp circuit in response to a plurality of the servo sectors;
- adjusting the first gain setting in response to a plurality of the data sectors;
- adjust a second gain setting of the VGA in order to adjust an amplitude of the amplified read signal based on a target response;
- and
- after adjusting the first gain setting in response to the data sectors, adjusting the cut-off filter when the second gain setting while reading the servo sectors is outside a range.
A disk drive comprising:
- a disk comprising a plurality of tracks defined by servo sectors, wherein each track comprises a plurality of data sectors;
- a head actuated over the disk;
- a preamp circuit operable to amplify a read signal emanating from the head to generate a pre-amplified read signal;
- and
- control circuitry operable to:
- calibrate a first gain setting of the preamp circuit in response to a plurality of the servo sectors;
- and
- adjust the first gain setting in response to a plurality of the data sectors;
- wherein prior to adjusting the first gain setting in response to the data sectors, the control circuitry is operable to adjust a fly height of the head.
A method of operating a disk drive comprising a disk including a plurality of tracks defined by servo sectors, wherein each track comprises a plurality of data sectors, a head actuated over the disk, and a preamp circuit operable to amplify a read signal emanating from the head to generate a pre-amplified read signal, the method comprising:
- calibrating a first gain setting of the preamp circuit in response to a plurality of the servo sectors;
- and
- adjusting the first gain setting in response to a plurality of the data sectors;
- wherein prior to adjusting the first gain setting in response to the data sectors, further comprising adjusting a fly height of the head.
Dependencies are inferred from the claim text.