Abstract: Various illustrative aspects are directed to a data storage device comprising a slider with a resistive temperature detector (RTD) having a first resistance electrically connected to a first amplifier and a plurality of controlled current sources and switches, and one or more processing devices configured to: control the switches to generate an alternating-bias signal having a first clock frequency for biasing the first resistance, modulate an input signal of the first amplifier using the first clock frequency to generate a modulated signal, demodulate an amplified modulated signal at an output of a second amplifier using the first clock frequency to generate a resistance detection signal, the second amplifier coupled to the first amplifier, and process the resistance detection signal to determine the first resistance and/or a change in value of the first resistance.

Abstract: Various illustrative aspects are directed to a data storage device comprising a disk; a read/write head configured to read data from and write data to the disk; a laser diode configured to heat an area of the disk near the read/write head; and one or more processing devices configured to preheat the laser diode to a target temperature associated with a write operation, wherein the preheating comprises applying (e.g., using a preamplifier) at least one forward bias pulse to the laser diode, wherein a corresponding duration of the at least one forward bias pulse is shorter than a duration of a turn-on delay for the laser diode; and initiate a write operation for writing data to the disk, based at least in part on the preheating.

Abstract: Various illustrative aspects are directed to a data storage device comprising a plurality of disks and actuator assemblies, each actuator assembly comprising one or more preamplifiers and one or more heads actuated over one of the plurality of disks, wherein each of the one or more heads comprises a read element and a write element. The data storage device further comprises a System on Chip (SoC) comprising one or more processing devices, a first and a second transmission line path between the SoC and a first and a second actuator assembly, respectively, where the first and the second transmission line path intersect at a matched point compensation (MPC), and wherein the one or more processing devices are configured to transmit write data to, or receive read data from, at least one preamplifier of the plurality of actuator assemblies.

Abstract: A semiconductor device includes semiconductor dies formed with through silicon vias (TSVs). The TSVs are coupled to contact pads in a surface of the semiconductor die by coils forming inductance loops at a number of contact pads. These inductance loops serve to distribute the capacitance at each bond pad along transmission lines, which distribution of the capacitance allows for a marked increase in read/write bandwidth for the semiconductor die.

Abstract: Various illustrative aspects are directed to a data storage device comprising a plurality of disks and actuator assemblies, each actuator assembly comprising one or more preamplifiers and one or more heads actuated over one of the plurality of disks, wherein each of the one or more heads comprises a read element and a write element. The data storage device further comprises a System on Chip (SoC) comprising one or more processing devices, a first and a second transmission line path between the SoC and a first and a second actuator assembly, respectively, where the first and the second transmission line path intersect at a matched point compensation (MPC), and wherein the one or more processing devices are configured to transmit write data to, or receive read data from, at least one preamplifier of the plurality of actuator assemblies.

Abstract: Various illustrative aspects are directed to a data storage device comprising a disk and a read/write head configured to read data from and write data to the disk. The read/write head comprises a write pole tip and a transducer configured near the write pole tip. One or more processing devices are mounted on or near the read/write head and generate an AC current that is applied to the transducer to cause the transducer to generate a high frequency auxiliary field that is applied to the disk. The one or more processing devices may be an RF source IC mounted on or near a slider on which the read/write head is integrated or mounted.

Abstract: Various illustrative aspects are directed to a data storage device comprising a slider with a resistive temperature detector (RTD) having a first resistance electrically connected to a first amplifier and a plurality of controlled current sources and switches, and one or more processing devices configured to: control the switches to generate an alternating-bias signal having a first clock frequency for biasing the first resistance, modulate an input signal of the first amplifier using the first clock frequency to generate a modulated signal, demodulate an amplified modulated signal at an output of a second amplifier using the first clock frequency to generate a resistance detection signal, the second amplifier coupled to the first amplifier, and process the resistance detection signal to determine the first resistance and/or a change in value of the first resistance.

Abstract: Various illustrative aspects are directed to a data storage device comprising a storage medium and a head configured to access the storage medium. The head comprises a first write assist element and a second write assist element. Control circuitry for driving the head is configured to apply a first write assist current Im that is synchronized to a write data current Iw to the first write assist element; and to apply a second DC write assist current Imdc to the second write assist element.

Abstract: Example channel circuits, data storage devices, and methods for asynchronous sampling from an oversampled analog-to-digital converter are described. The channel circuit may include an analog-to-digital converter configured to generate an oversampled digital signal from an analog data signal using a sample rate that is an integer multiple of the baud rate of the channel circuit. A digital sample interpolator may then interpolate interpolated digital signal values from multiple signal values of the oversampled digital signal and select values at baud rate to generate a baud rate digital signal. The baud rate digital signal may be used by an iterative detector in a timing loop and, once a target timing is achieved, for the iterative detector to detect data bits from the interpolated digital signal.

Abstract: A data storage device is disclosed comprising a storage medium and a head configured to access the storage medium, wherein the head comprises a first write assist element (WA1) comprising a first terminal and a second terminal and a second write assist element (WA2) comprising a first terminal and a second terminal. The second terminal of the WA1 and the second terminal of the WA2 are coupled together to form a common node. A first bias signal is applied to the first terminal of the WA1, a second bias signal is applied to the first terminal of the WA2, and a common mode voltage is applied to the common node.

Abstract: A data storage device is disclosed comprising a head actuated over a magnetic media, wherein the head comprises a read element configured to generate a read signal when reading data from the magnetic media. A common-source common-gate (CS-CG) differential amplifier is coupled to the read element through a transmission line having a transmission line impedance Z0. A feedback circuit is coupled between an output of the CS-CG differential amplifier and an input of the CS-CG differential amplifier, wherein the feedback circuit is configured so that an input impedance of the CS-CG differential amplifier substantially matches the transmission line impedance Z0.

Abstract: A semiconductor device is disclosed including a wire bonded die stack where the bond wires skip dies in the die stack to provide bond wires having a long length. In one example, the semiconductor dies are stacked on top of each other with offsets along two orthogonal axes so that the dies include odd numbered dies interspersed and staggered with respect to even numbered dies only one of the axes. Wire bonds may be formed between the odd numbered dies, skipping the even numbered dies, and wire bonds may be formed between the even numbered dies, skipping the odd numbered dies. The long length of the bond wires increases an inductance of the wire bonds relative to parasitic capacitance of the semiconductor dies, thereby increasing signal path bandwidth of the semiconductor device.

Abstract: A data storage device is disclosed comprising a head actuated over a magnetic media, wherein the head comprises a read element configured to generate a read signal when reading data from the magnetic media. A common-source common-gate (CS-CG) differential amplifier is coupled to the read element through a transmission line having a transmission line impedance Z0. A feedback circuit is coupled between an output of the CS-CG differential amplifier and an input of the CS-CG differential amplifier, wherein the feedback circuit is configured so that an input impedance of the CS-CG differential amplifier substantially matches the transmission line impedance Z0.

Abstract: A data storage device is disclosed comprising a head actuated over a magnetic media, wherein the head comprises a write element and a first read element. A preamp circuit comprising an interface includes at least a write line associated with the write element of the head and a first read line associated with the first read element of the head. A first read signal is received from the preamp circuit over the first read line during a read operation, and configuration data is transmitted to the preamp circuit over the first read line during a write operation.

Abstract: A method of operating a data storage device is disclosed comprising an enclosure comprising a first head actuated over a first disk surface and a second head actuated over a second disk surface. A manufacture printed circuit board (PCB) is coupled to the enclosure, wherein the manufacture PCB comprises at least one dual channel configured to execute concurrent access operations. While the manufacture PCB is coupled to the enclosure, the data storage device is operated as a dual channel device. The manufacture PCB is decoupled from the enclosure and a product PCB is coupled to the enclosure, wherein the product PCB comprises a single channel configured to execute a single access operation.

Abstract: A data storage device is disclosed comprising a top head actuated over a top surface of a first disk, a bottom head actuated over a bottom surface of the first disk, a top head actuated over a top surface of a second disk, and a bottom head actuated over a bottom surface of the second disk. A dual channel preamp circuit is coupled to the top and bottom heads of the first and second disks, wherein a selection signal is applied to the dual channel preamp circuit to select between the first disk and the second disk. A concurrent access operation of the top and bottom surface of the selected disk is executed using the dual channel preamp circuit.

Abstract: A semiconductor device is disclosed including a wire bonded die stack where the bond wires skip dies in the die stack to provide bond wires having a long length. In one example, the semiconductor dies are stacked on top of each other with offsets along two orthogonal axes so that the dies include odd numbered dies interspersed and staggered with respect to even numbered dies only one of the axes. Wire bonds may be formed between the odd numbered dies, skipping the even numbered dies, and wire bonds may be formed between the even numbered dies, skipping the odd numbered dies. The long length of the bond wires increases an inductance of the wire bonds relative to parasitic capacitance of the semiconductor dies, thereby increasing signal path bandwidth of the semiconductor device.

Abstract: Embodiments disclosed herein generally relate to a method for monitoring optical power in a HAMR device. In one embodiment, the method includes enhancing a thermal sensor bandwidth through advanced electrical detection techniques. The advanced electrical detection techniques include obtaining calibration waveform data for a thermal sensor by calibrating the thermal sensor, obtaining real-time waveform data for the thermal sensor that may deviate from the calibration waveform data, updating the calibration waveform data to include the real-time waveform data, repeating obtaining real-time waveform data and updating the calibration waveform data during writing operations. By updating the calibration waveform data, the bandwidth of the thermal sensor is determined by a fixed sampling time interval, and the thermal sensor rise time to steady state would not be a limitation to its response time.

Abstract: Embodiments disclosed herein generally relate to a method for monitoring optical power in a HAMR device. In one embodiment, the method includes enhancing a thermal sensor bandwidth through advanced electrical detection techniques. The advanced electrical detection techniques include obtaining calibration waveform data for a thermal sensor by calibrating the thermal sensor, obtaining real-time waveform data for the thermal sensor that may deviate from the calibration waveform data, updating the calibration waveform data to include the real-time waveform data, repeating obtaining real-time waveform data and updating the calibration waveform data during writing operations. By updating the calibration waveform data, the bandwidth of the thermal sensor is determined by a fixed sampling time interval, and the thermal sensor rise time to steady state would not be a limitation to its response time.

Abstract: Embodiments disclosed herein generally relate to a method for monitoring optical power in a HAMR device. In one embodiment, the method includes enhancing a thermal sensor bandwidth through advanced electrical detection techniques. The advanced electrical detection techniques include obtaining calibration waveform data for a thermal sensor by calibrating the thermal sensor, obtaining real-time waveform data for the thermal sensor that may deviate from the calibration waveform data, updating the calibration waveform data to include the real-time waveform data, repeating obtaining real-time waveform data and updating the calibration waveform data during writing operations. By updating the calibration waveform data, the bandwidth of the thermal sensor is determined by a fixed sampling time interval, and the thermal sensor rise time to steady state would not be a limitation to its response time.