Data storage device with jitter-based touchdown detection
AssigneeWestern Digital Technologies, Inc.
InventorsNoureddine Kermiche, Robert Eaton
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Abstract
A data storage device comprises a disk, a recording head, and a thermal fly-height control (TFC) actuator. Write touchdown is detected by writing a reference pattern to the disk at a target TFC power, reading the reference pattern at operational TFC power, detecting write touchdown when a measured timing jitter exceeds a threshold, and writing additional reference patterns to the magnetic storage medium at incrementally adjusted target TFC powers until write touchdown is detected. For read touchdown detection, the reference pattern is written at a target TFC power and read at operational TFC power, and re-read at incrementally adjusted target TFC powers until read touchdown is detected.
Claims20
A data storage device comprising:
- a magnetic storage medium;
- a recording head configured to write data to and read data from the magnetic storage medium;
- a thermal fly-height control (TFC) actuator configured to adjust spacing between the recording head and the magnetic storage medium;
- and
- one or more processing devices or components, configured individually or in combination, to detect touchdown of the recording head on the magnetic storage medium by:
- writing a reference pattern to the magnetic storage medium at a target TFC power;
- reading the reference pattern written to the magnetic storage medium at an operational TFC power;
- measuring timing jitter from the read reference pattern;
- when the measured timing jitter exceeds a threshold, detecting a write touchdown;
- and
- when the measured timing jitter does not exceed the threshold, writing additional reference patterns to the magnetic storage medium at incrementally adjusted target TFC powers until the measured timing jitter exceeds the threshold.
A data storage device comprising:
- a magnetic storage medium;
- a recording head configured to write data to and read data from the magnetic storage medium;
- a thermal fly-height control (TFC) actuator configured to adjust spacing between the recording head and the magnetic storage medium;
- and
- one or more processing devices or components, configured individually or in combination, to detect touchdown of the recording head on the magnetic storage medium by:
- reading, at a target TFC power, a reference pattern written to the magnetic storage medium at an operational TFC power;
- measuring timing jitter from the read reference pattern;
- when the measured timing jitter exceeds a threshold, detecting a read touchdown;
- and
- when the measured timing jitter does not exceed the threshold, re-reading the reference pattern at incrementally adjusted target TFC powers until the measured timing jitter exceeds the threshold.
A method for detecting touchdown of a recording head on a magnetic storage medium of a data storage device, the method comprising:
- writing a reference pattern to the magnetic storage medium at a target thermal fly-height control (TFC) power;
- reading the reference pattern written to the magnetic storage medium at an operational TFC power;
- measuring timing jitter from the read reference pattern;
- when the measured timing jitter exceeds a threshold, detecting a write touchdown;
- and
- when the measured timing jitter does not exceed the threshold, writing additional reference patterns to the magnetic storage medium at incrementally adjusted target TFC powers until the measured timing jitter exceeds the threshold.
A method for detecting touchdown of a recording head on a magnetic storage medium of a data storage device, the method comprising:
- reading, at a target thermal fly-height control (TFC) power, a reference pattern written to the magnetic storage medium at an operational TFC power;
- measuring timing jitter from the read reference pattern;
- when the measured timing jitter exceeds a threshold, detecting a read touchdown;
- and
- when the measured timing jitter does not exceed the threshold, re-reading the reference pattern at incrementally adjusted target TFC powers until the measured timing jitter exceeds the threshold.
Dependencies are inferred from the claim text.