Abstract: Method and apparatus for detecting head disk interference (HDI). In accordance with some embodiments, a bias calibration circuit is adapted to respectively bypass or amplify a head disk interference (HDI) signal output from an HDI sensor responsive to a bias voltage adjusted according to a first control signal. A detection circuit is adapted to compare a swing range of a signal output from the bias calibration circuit and a swing range of a reference signal, and to output the first control signal responsive to said comparison.

Abstract: A method of operating a pre-amplifier of a hard disk drive is provided. The method includes generating a comparison signal corresponding to a result of comparing a reference signal with a difference between differential signals corresponding to write data, and controlling transmission of the differential signals to a write head in response to the comparison signal.

Abstract: Method and apparatus for detecting head disk interference (HDI). In accordance with some embodiments, a bias calibration circuit is adapted to respectively bypass or amplify a head disk interference (HDI) signal output from an HDI sensor responsive to a bias voltage adjusted according to a first control signal. A detection circuit is adapted to compare a swing range of a signal output from the bias calibration circuit and a swing range of a reference signal, and to output the first control signal responsive to said comparison.

Abstract: Apparatus and method for controlling a fly height of a transducer adjacent a recording surface by adjusting a write voltage magnitude. In accordance with some embodiments, a write voltage with an initial magnitude is applied to a transducer. A write voltage change interval and a write voltage change amount are selected. The magnitude of the applied write voltage is thereafter successively reduced by the write voltage change amount over each of a plurality of successive write voltage change intervals.

Abstract: A method of operating a pre-amplifier of a hard disk drive is provided. The method includes generating a comparison signal corresponding to a result of comparing a reference signal with a difference between differential signals corresponding to write data, and controlling transmission of the differential signals to a write head in response to the comparison signal.

Abstract: Optimal write current of a data storage device is determined by writing test data with an initial write condition and evaluating a performance related to the pole tip protrusion (PTP) of a magnetic head. A PTP control duration is determined as a duration between where the test data is initially written and where a performance evaluation value begins to satisfy a threshold criterion. An overshoot value of a PTP control signal that determines an overshoot amplitude of a write current and a PTP control duration are determined by for writing subsequent data such that PTP-related data errors are substantially constant regardless of write time.

Abstract: Optimal write current of a data storage device is determined by writing test data with an initial write condition and evaluating a performance related to the pole tip protrusion (PTP) of a magnetic head. A PTP control duration is determined as a duration between where the test data is initially written and where a performance evaluation value begins to satisfy a threshold criterion. An overshoot value of a PTP control signal that determines an overshoot amplitude of a write current and a PTP control duration are determined by for writing subsequent data such that PTP-related data errors are substantially constant regardless of write time.