Abstract: A disk drive dynamic wave shaper (DWS) write driver includes a write current generator that produces a baseline output current for the write current pulses and an overshoot current generator that produces an overshoot current with different values. The overshoot current is added to the baseline current, with the value of the overshoot current amplitude (OSA) being selected in response to the frequency of transitions in the write data signal. The write driver includes logic circuitry that detects the pattern of transitions. Transitions that are immediately followed by a transition will receive a larger-than-nominal OSA1, transitions that are not immediately followed by a transition and that are not preceded by a long sequence of non-transitions will receive a nominal OSA2, and transitions after longer sequences of non-transitions will receive a smaller-than-nominal OSA3.

Abstract: A method, apparatus, and system are provided for implementing noise based detection of spin-torque oscillator (STO) power on for microwave assisted magnetic recording (MAMR) hard disk drives (HDDs). A low frequency noise generated by a spin-torque oscillator, such as noise in a frequency range between 10 kHz and 100 MHz, is detected. The detected STO noise is compared to a predefined threshold to identify STO power on operation.

Abstract: A method, apparatus, and system are provided for implementing a power-on spin-torque oscillator (STO) oscillation checker to monitor STO resistance to identify STO oscillation with microwave assisted magnetic recording (MAMR) hard disk drives (HDDs). An amplitude modulated write coil drive current is applied to the write coil in the presence of a DC bias current applied to the STO. The amplitude modulated write coil drive current modulates the STO resistance monitored using an amplifier circuit to identify STO oscillation, used to ensure stable MAMR HDD write operation.

Abstract: Disk drive embodiments with common lead connections in the slider, suspension, and preamplifier are described. The arm electronics IC includes a preamplifier with single-ended input from the set of signal traces that include a common signal return lead for the plurality of read transducers (readers) in the slider. Two embodiments of the preamps are described that include a single-ended design and a pseudo-single-ended design. Each embodiment supplies the required bias to each read transducer using an operational transconductance amplifier (OTA) that drives a variable current source connected to the transducer. The positive input to the OTA is a DC voltage with the AC signal from the transducer imposed on it. The negative input is a DC reference voltage. Various embodiments of the signal trace configuration on the suspension are described including a single and double layer embodiments.

Abstract: Disk drive embodiments with common lead connections in the slider, suspension, and preamplifier are described. The arm electronics IC includes a preamplifier with single-ended input from the set of signal traces that include a common signal return lead for the plurality of read transducers (readers) in the slider. Two embodiments of the preamps are described that include a single-ended design and a pseudo-single-ended design. Each embodiment supplies the required bias to each read transducer using an operational transconductance amplifier (OTA) that drives a variable current source connected to the transducer. The positive input to the OTA is a DC voltage with the AC signal from the transducer imposed on it. The negative input is a DC reference voltage. Various embodiments of the signal trace configuration on the suspension are described including a single and double layer embodiments.

Abstract: A method, apparatus, and system are provided for implementing a power-on spin-torque oscillator (STO) oscillation checker to monitor STO resistance to identify STO oscillation with microwave assisted magnetic recording (MAMR) hard disk drives (HDDs). A changing bias current is applied to the STO in the presence of constant write drive current. The STO bias current is changed to observe sudden changes in STO resistance monitored using a differentiator circuit to identify STO oscillation, used to ensure stable MAMR HDD write operation.

Abstract: The subject disclosure is directed towards loading parallel memories (e.g., in one or more FPGAs) with multidimensional data in an interleaved manner such that a multidimensional patch/window may be filled with corresponding data in a single parallel read of the memories. Depending on the position of the patch, the data may be rotated horizontally and/or vertically, for example, so that the data in each patch is consistently arranged in the patch regardless of from which memory each piece of data was read. Also described is leveraging dual ported memory for multiple line reads and/or loading one part of a buffer while reading from another.

Abstract: Approaches for a hard-disk drive (HDD) having a balanced resistive temperature detector (RTD). A HDD includes a head slider comprising a single RTD. A read/write IC comprises a balance resistor having the same resistance as the single RTD when the head slider is not in physical contact with the disk. The same amount of current flows through the single RTD and the balance resistor except when the head slider is in physical contact with the disk. Detecting a voltage change across the single RTD enables physical contact between the head slider and the disk to be accurately detected using a circuit with low noise. Alternately, the head slider may include two RTDs connected in sequence, and the balance resistor may possess the same resistance as the two RTDs. The two RTDs may vary inversely with environmental changes to avoid the need to recalibrate the balance resistor after any environmental change.

Abstract: Embedded contact sensor controls for use in arm electronics (AE) in a disk drive are described that provide for removing undesirable offsets between the measured voltage across the ECS resistor in the slider and the balance resistor in ECS amplifier in the arm electronics (AE), which allows increased amplification of the resulting adjusted signal without saturation. Embodiments include a Zero-Offset Circuit, which can be activated periodically or on demand to sample and hold the present DC offset voltage in the ECS amplifier signal and subtract the DC offset voltage from ECS amplifier signal. The adjusted signal can then be further amplified without saturation.

Abstract: The present disclosure describes a method and system for providing location-aware services. The method enables location-aware business service providers to obtain location-aware services for their users without having to develop and maintain computer software or server systems to provide such services. The disclosed method may also allow location-aware business service providers to customize a generic client system for use by their users, thereby eliminating the need for location-aware business service providers to develop specialized computer software to manage the location-aware services.

Abstract: A method of coating an article includes the steps of providing a powder comprising coated particles; and spray coating the powder onto a surface of the article to form a composite coating. The spray coating may be carried out by combustion spraying, gas plasma spraying, including vacuum plasma spraying (VPS), and cold spraying. The article may be an implant for surgical or dental use. The powder may include particles of metal coated calcium phosphates, especially metal coated hydroxyapatite. The particles may include bioactive agents.

Abstract: A method, apparatus, and system are provided for implementing spin-torque oscillator (STO) sensing with a demodulator for hard disk drives. The demodulator measures an instantaneous phase of the readback signal from a STO sensor and converts the readback signal into a signal that is proportional to the magnetic field affecting the STO frequency during a bit time. The converted signal is used for processing by conventional data detection electronics.

Abstract: A method, apparatus, and system are provided for implementing spin-torque oscillator sensing with an enhanced integrated demodulator for hard disk drives. The demodulator receives an input signal from a STO read sensor having an oscillation frequency ? related to the strength of the detected magnetic signal field. The demodulator includes a pair of mixers coupled to a quadrature reference oscillator with respective quadrature components cos(?0t), and sin(?0t) of the quadrature reference oscillator being mixed with a received input signal to form signals at the sum and difference frequencies, ?±?0. Each of these mixer products is lowpass filtered by a respective a lowpass filter to remove the sum frequency components for providing a demodulator output signal that is directly proportional the STO oscillation frequency ?. The demodulator output signal is used for processing by data detection electronics.

Abstract: A method, apparatus, and system for implementing spin-torque oscillator (STO) sensing with an enhanced delay control feedback circuit for hard disk drives. A detector receives an input signal from a STO read sensor having an oscillation frequency related to the strength of the detected magnetic signal field. The received input signal is mixed with a time delayed input signal for providing a detector output signal. A low frequency component signal of the detector output signal is monitored and a delay control feedback is applied to an adjustable time delay to bias the DC signal of the detector output signal.

Abstract: Approaches for a distributed temperature detector architecture in a head disk interface system of a hard-disk drive (HDD). A HDD may include a read/write head comprising a read element and a write element and a read/write integrated circuit (IC). The read/write head may comprise (a) a first temperature sensor that is located relatively near an air bearing surface (ABS) of the read/write head and (b) a second temperature sensor that is offset from the ABS. The read/write IC is configured to detect when the read/write head makes physical contact with a disk based on a difference in temperature measured by the first and second temperature sensor. The first and second temperature sensors form a bridge circuit, such as a Wheatstone bridge, with a first IC resistor and a second IC resistor that both reside in the read/write IC, allowing the temperature of the read/write head to be accurately measured.

Abstract: Approaches for a distributed temperature detector architecture in a head disk interface system of a hard-disk drive (HDD). A HDD may include a read/write head comprising a read element and a write element and a read/write integrated circuit (IC). The read/write head may comprise (a) a first temperature sensor that is located relatively near an air bearing surface (ABS) of the read/write head and (b) a second temperature sensor that is offset from the ABS. The read/write IC is configured to detect when the read/write head makes physical contact with a disk based on a difference in temperature measured by the first and second temperature sensor. The first and second temperature sensors form a bridge circuit, such as a Wheatstone bridge, with a first IC resistor and a second IC resistor that both reside in the read/write IC, allowing the temperature of the read/write head to be accurately measured.

Abstract: Approaches for a hard-disk drive (HDD) having a balanced resistive temperature detector (RTD). A HDD includes a head slider comprising a single RTD. A read/write IC comprises a balance resistor having the same resistance as the single RTD when the head slider is not in physical contact with the disk. The same amount of current flows through the single RTD and the balance resistor except when the head slider is in physical contact with the disk. Detecting a voltage change across the single RTD enables physical contact between the head slider and the disk to be accurately detected using a circuit with low noise. Alternately, the head slider may include two RTDs connected in sequence, and the balance resistor may possess the same resistance as the two RTDs. The two RTDs may vary inversely with environmental changes to avoid the need to recalibrate the balance resistor after any environmental change.

Abstract: A method, apparatus, and system are provided for implementing spin-torque oscillator (STO) sensing with a demodulator for hard disk drives. The demodulator measures an instantaneous phase of the readback signal from a STO sensor and converts the readback signal into a signal that is proportional to the magnetic field affecting the STO frequency during a bit time. The converted signal is used for processing by conventional data detection electronics.

Abstract: A method, apparatus, and system for implementing spin-torque oscillator (STO) sensing with an enhanced delay control feedback circuit for hard disk drives. A detector receives an input signal from a STO read sensor having an oscillation frequency related to the strength of the detected magnetic signal field. The received input signal is mixed with a time delayed input signal for providing a detector output signal. A low frequency component signal of the detector output signal is monitored and a delay control feedback is applied to an adjustable time delay to bias the DC signal of the detector output signal.

Abstract: A method, apparatus, and system are provided for implementing spin-torque oscillator sensing with an enhanced integrated demodulator for hard disk drives. The demodulator receives an input signal from a STO read sensor having an oscillation frequency ? related to the strength of the detected magnetic signal field. The demodulator includes a pair of mixers coupled to a quadrature reference oscillator with respective quadrature components cos(?0t), and sin(?0t) of the quadrature reference oscillator being mixed with a received input signal to form signals at the sum and difference frequencies, ?±?0. Each of these mixer products is lowpass filtered by a respective a lowpass filter to remove the sum frequency components for providing a demodulator output signal that is directly proportional the STO oscillation frequency ?. The demodulator output signal is used for processing by data detection electronics.