Abstract: An apparatus may include a preamplifier configured to implement multiple operational modes and configured to be connected to a magnetic read/write head, wherein the magnetic read/write head includes a read sensor to read data from a disk and a write element to write data to the disk. The preamplifier may further include an input configured to receive a test mode control signal to activate a mode monitoring mode of one or more test modes of a test mode circuit of the preamplifier, the test mode circuit configured to determine an indicator of the current operational mode of the preamplifier, and an output to provide the determined indicator of the current operational mode of the preamplifier.

Abstract: A method of forming a recording head for use with a data storage medium in a data storage device. The method includes forming first and second writers of different target geometries. A first recording measurement is performed on one or more storage media using the first writer. A second recording measurement is performed on the one or more storage media using the second writer. Based on a comparison of the first and second recording measurements to a predetermined quantity, either the first writer or the second writer is selected to be operational in the data storage device.

Abstract: A slider configured for heat-assisted magnetic recording includes a laser diode optically coupled to a waveguide of the slider. A power supply is coupled to the laser diode. A preamplifier is coupled to the power supply. The preamplifier is configured to monitor a forward voltage across the laser diode while operating the laser diode at a constant current during a write operation, detect a change in the forward voltage indicative of laser power instability, and generate a signal in response to detecting the forward voltage change.

Abstract: An apparatus may include a preamplifier configured to be connected to a plurality of magnetic read/write heads, wherein each of the magnetic read/write heads includes a read sensor to read data from a disc and a write element to write data to the disc. The preamplifier may include a first set of registers configured to indicate a first head of the plurality of magnetic read/write heads that is selected for reading data, a second set of registers configured to indicate a second head of the plurality of magnetic read/write heads that is selected for reading data, an input line configured to receive a control signal to activate reading data from the first head substantially simultaneously with reading data from the second head, a first output to provide data from the first head, and a second output to provide data from the second head.

Abstract: A contact sensor is provided at or near an air bearing surface of a slider and having a temperature coefficient of resistance. The contact sensor is coupled to a lead arrangement comprising a first lead and a second lead. The contact sensor comprises a sensor element, a first peripheral wing comprising an inner wing connected to the sensor element and an outer wing connected to the first lead, and a second peripheral wing comprising an inner wing connected to the sensor element and an outer wing connected to the second lead. An electrically conductive overlay covers at least the outer wings of the first and second peripheral wings and some or all of the first and second electrical leads.

Abstract: Apparatuses having variable communication speeds are disclose. In one example, an apparatus may comprise a controller configured to: receive a signal from a host, the signal being compatible with a data communication protocol at a first data communication speed; selectively implement a first data communication protocol from a plurality of data communication protocols to communicate with a first memory or implement a second data communication protocol from the plurality of data communication protocols to communicate with a second memory based on the data communication speed; store data in the first memory via the first data communication protocol when the data communication speed is a first speed; and store data in the second memory via the second data communication protocol when the data communication speed is a second speed that is different than the first speed.

Abstract: A magnetic recording medium includes a recording surface comprising a first recording layer having a first ferromagnetic resonant frequency and a second recording layer having a second ferromagnetic resonant frequency. The first recording layer is configured for storing user data and the second recording layer configured for storing servo data. A recording head arrangement is configured for microwave-assisted magnetic recording (MAMR) and writing user data to the first recording layer. The recording head arrangement comprises a write pole configured to generate a write magnetic field, and a write-assist arrangement proximate the write pole. The write-assist arrangement is configured to generate a radiofrequency assist magnetic field at a frequency that corresponds to the first ferromagnetic resonant frequency. A reader of the recording head arrangement is configured to read combined signals from the first and second recording layers.

Abstract: One or more magnetic recording disks are coupled to a spindle motor, each of the disks having opposing recording surfaces. Two or more actuators are moveable independently over at least a first recording surface of the one or more disks. A first actuator of the two or more actuators comprises a first write head and a first read head. A second actuator of the two or more actuators comprises at least a second read head and may include a second write head. A controller is coupled to the two or more actuators and configured to write data to a track on the first recording surface using the first write head, and perform a read operation on the data written to the track using the second read head. The controller is also configured to verify that the data was successfully written to the track in response to the read operation. The read operation can be performed within less than one revolution of the first recording surface after the write operation.

Abstract: A data storage system may have a first data storage device and a second data storage device connected with a host via a network. The network can consist of a network controller having a message module that generates a buffer progression plan and then assigns a first system message to a first buffer and first computing unit of the first data storage device and assigns a second system message to a second buffer and second computing unit of the second data storage device. The respective first and second computing units may then service the first and second system messages.

Abstract: A heat-assisted magnetic recording media structure with exchange-coupled composite layer structure may be utilized in a data storage device. The heat-assisted magnetic recording disk structure can have a FePt-based layer as a storage layer and a FePt-based or a CoPt-based magnetic layer with higher Curie temperature as a write layer. The interface between the write layer and the storage layer may be separated by an exchange control layer. The composite structure can be optimized to reduce jitter for high density data storage by tuning the exchange coupling between the write layer and storage layer.

Abstract: A slider comprises an air bearing surface (ABS) and is configured to interact with a magnetic recording medium. A writer is provided on the slider and comprises a write coil having a media-facing surface situated at the ABS. Cooling arms project laterally from peripheral surfaces of the write coil and extend along the ABS. The media-facing surface of the write coil and the cooling arms are exposed to the ABS to facilitate increased cooling of the write coil at the ABS.

Abstract: A recording head has a near-field transducer proximate a media-facing surface of the recording head. A waveguide core overlaps and delivers light from a light source to the near-field transducer. The waveguide core has a dielectric cavity proximate the near-field transducer. The cavity is filled with a cladding material and reduces optical feedback to the light source.

Abstract: A data storage device with one or more buffers can employ buffer tenure management with at least a data storage device having a first buffer, a second buffer, a buffer manager, and a non-volatile memory. The first buffer can be located on-chip while the second buffer is located off-chip. The first buffer may be filled with data having a tenure of less than a predetermined tenure threshold as directed by the buffer manager.

Abstract: An apparatus comprises a light source configured to generate light, and a modulator coupled to the light source and configured to modulate the light above a predetermined frequency. A slider is configured for heat-assisted magnetic recording and to receive the modulated light. A resistive sensor is integral to the slider and subject to heating by absorption of electromagnetic radiation and conduction of heat. Measuring circuitry is coupled to the resistive sensor and configured to measure a response of the resistive sensor due to absorbed electromagnetic radiation and not from the heat conduction. The measuring circuitry may further be configured to determine output optical power of the light source using the measured resistive sensor response.

Abstract: Apparatus and method contemplating a magnetoresistive memory apparatus having a read element having a high resistance material selected to optimize read sensitivity and a write element having a material selected for a lower critical current response than the read element critical current response to optimize switching efficiency, wherein the read element resistance is higher than the write element resistance, and a shared storage space for both elements.

Abstract: A recording head has a near-field transducer overlapping a core near a media-facing surface of the recording head. The near-field transducer has an enlarged portion formed of a plasmonic material and a peg extending from the enlarged portion. The enlarged portion includes a stacked feature that reduces the emission of a polarization rotated portion of light to a recording medium.

Abstract: Dynamically varying Over-Provisioning (OP) enables improvements in lifetime, reliability, and/or performance of a Solid-State Disk (SSD) and/or a flash memory therein. A host coupled to the SSD writes newer data to the SSD. If the newer host data is less random than older host data, then entropy of host data on the SSD decreases. In response, an SSD controller dynamically alters allocations of the flash memory, decreasing host allocation and increasing OP allocation. If the newer host data is more random, then the SSD controller dynamically increases the host allocation and decreases the OP allocation. The SSD controller dynamically allocates the OP allocation between host OP and system OP proportionally in accordance with a ratio of bandwidths of host and system data writes to the flash memory. Changes in allocations are selectively made in response to improved compression or deduplication of the host data, or in response to a host command.

Abstract: A method for assembling a head-gimbal assembly of a hard disk drive, the method including the steps of dispensing adhesive onto a top surface of a gimbal tongue, wherein the gimbal tongue is positioned adjacent to a load beam with a dimple extending from its top surface, and wherein the gimbal tongue is configured with at least one support feature that inhibits its deformation toward the dimple when subjected to downward pressure with respect to the dimple; positioning a slider on which a magnetic head is mounted adjacent to the top surface of the gimbal tongue; and pressing the slider onto the adhesive and toward the dimple of the load beam.

Abstract: Systems and methods are disclosed for detection of a selected signal pattern, such as a servo sector preamble, and for frequency offset determination. A circuit may be configured to divide a signal into detection windows of a selected size, and sample the signal a selected number of times within each detection window. The circuit may then determine an error value for each detection window based on values of the samples for each detection window, and determine the preamble is detected when a threshold number of most-recently sampled detection windows have error values below a threshold value. The circuit may then organize the sample values corresponding to the preamble into groups, and calculate phase estimates representing a phase at which the groups were sampled. The circuit may determine a frequency offset based on the phase estimates, and modulate the sampling frequency according to the frequency offset.