Write current undershoot for a heat-assisted magnetic storage device
AssigneeSeagate Technology LLC
InventorsYanzhang Liu, Zhen Wei, Jianhua Xue, Olle Gunnar Heinonen, Michael Allen Seigler
Life of this patent
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Abstract
An apparatus includes a write head. A preamplifier is coupled to the write head. A controller is coupled to the preamplifier and configured to cause the preamplifier to apply an overshoot current to the write head for a predefined overshoot current duration, apply an undershoot current to the write head for a predefined undershoot current duration, and apply a steady-state current to the write head after the undershoot current duration, the steady-state current being greater than the undershoot current.
Claims20
A heat-assisted magnetic recording device, comprising:
- a write head comprising a near-field transducer configured to transmit energy to create a thermal spot on a recording medium;
- and
- a preamplifier coupled to the write head;
- and
- a controller coupled to the preamplifier and configured to cause the preamplifier to:
- apply an overshoot current to the write head for a predefined overshoot current duration during writing of a bit;
- apply an undershoot current to the write head for a predefined undershoot current duration during writing the bit;
- and
- apply, after the undershoot current duration, a steady-state current to the write head during writing the bit and while the near-field transducer is transmitting energy to the recording medium, the steady-state current being greater than the undershoot current.
A method for modulating current in a heat assisted magnetic recording device comprising:
- applying an overshoot current to a write head for a predefined overshoot current duration during writing of a bit;
- applying an undershoot current to the write head for a predefined undershoot current duration during writing of the bit;
- and
- applying, after the undershoot current duration, a steady-state current to the write head during writing of the bit and while a near-field transducer is transmitting energy to a recording medium, the steady-state current being greater than the undershoot current.
An apparatus, comprising:
- an interface circuit operable to communicate with a write head, the write head comprising a near-field transducer configured to transmit energy to create a thermal spot on a recording medium;
- a controller coupled to the interface circuit, the controller operable to provide instructions to the interface circuit to:
- apply an overshoot current to the write head for a predefined overshoot current duration during writing of a bit;
- apply an undershoot current to the write head for a predefined undershoot current duration during writing of the bit;
- and
- apply, after the undershoot current duration, a steady-state current to the write head during writing the bit and while the near-field transducer is transmitting energy to the recording medium, the steady-state current being greater than the undershoot current.
Dependencies are inferred from the claim text.