Abstract: An active low-power termination circuit includes a first leg of a pair of transistors connected in series between the high supply level and ground, where the termination input is at a node between the transistors of the first node. A second leg uses a feed forward mechanism to control the voltage levels on the control gates of the transistors of the first leg. The second leg includes a second pair diode connected transistors, each of which is has its control gate connected to the control gate of the corresponding transistor in the first leg. A variable current source connected in series with the transistors of the second leg and is controlled by the output of a difference amplifier that has one input connect to an intermediate node of the second leg and a second input connected to a reference level intermediate to the high supply level and ground.

Abstract: Disclosed herein are suspension assembly structures for data storage devices that include physical or virtual crossovers of the pairs of differential signal traces to improve immunity to crosstalk and other interference. In an embodiment, the suspension assembly structure comprises a first trace for carrying a first component of a current to a differential transducer on a slider, a second trace for carrying a second component of the current to the differential transducer on the slider, and third and fourth traces for providing a differential write current to a writer of the data storage device, wherein the first trace physically crosses over the second trace at a first distance from a tail of the suspension assembly structure.

Abstract: Disclosed herein are suspension assembly structures for data storage devices that include physical or virtual crossovers of the pairs of differential signal traces to improve immunity to crosstalk and other interference. In an embodiment, the suspension assembly structure comprises a first trace for carrying a first component of a current to a differential transducer on a slider, a second trace for carrying a second component of the current to the differential transducer on the slider, and third and fourth traces for providing a differential write current to a writer of the data storage device, wherein the first trace physically crosses over the second trace at a first distance from a tail of the suspension assembly structure.

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: A data storage device is disclosed comprising a head actuated over a disk, wherein the head comprises a first sensor element and a second sensor element. When configured into a first single-ended mode, a bias signal is applied to the first sensor element to generate a first single-ended output signal based on a response of the first sensor element, and when configured into a second single-ended mode, the bias signal is applied to the second sensor element to generate a second single-ended output signal based on a response of the first sensor element. When configured into a differential mode, the bias signal is concurrently applied to the first sensor element and the second sensor element to generate a differential output signal based on a response of the first sensor element and the second sensor element.

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: A multiple-segment transmission line in a hard disk drive enables a wider optimization range of the slope, duration and amplitude of the transmission line overshoot (TLO) wave shape. There is a first segment with two traces for connection to the write driver circuitry, an end segment with two traces for connection to the write head and at least two intermediate segments. The number of traces in a segment is different from the number of traces in the segments to which the segment is immediately connected. There is an even number of traces in each segment and the traces in each segment are interleaved. The number of segments and the number of traces in each segment can be selected to achieve the desired impedance levels for the different segments to achieve the desired wave shape for the TLO. All of the traces on the transmission line are preferably coplanar.

Abstract: A multiple-segment transmission line in a hard disk drive enables a wider optimization range of the slope, duration and amplitude of the transmission line overshoot (TLO) wave shape. There is a first segment with two traces for connection to the write driver circuitry, an end segment with two traces for connection to the write head and at least two intermediate segments. The number of traces in a segment is different from the number of traces in the segments to which the segment is immediately connected. There is an even number of traces in each segment and the traces in each segment are interleaved. The number of segments and the number of traces in each segment can be selected to achieve the desired impedance levels for the different segments to achieve the desired wave shape for the TLO. All of the traces on the transmission line are preferably coplanar.

Abstract: The embodiments disclosed generally relate to a read device in a magnetic recording head. The read device uses parametric excitation to injection lock the STO to an external AC signal with a frequency that is two times the resonance frequency, or more. The field from the media acting on the STO causes a change in the phase between the STO output and the external locking signal, which can be monitored using a phase detection circuit. The injection locking improves the STO signal to noise ratio and simplifies the detection circuit.

Abstract: An interleaved conductor structure for electrically connecting the read/write electronics to a read/write head in a hard disk drive is provided. The interleaved conductor structure may allow for an increased characteristic-impedance range, greater interference shielding and a reduction of signal loss that is contributed by a lossy conductive substrate. The electrical traces may have different widths, be offset, or even wrap around each other at the via connections.

Abstract: An interleaved conductor structure for electrically connecting the read/write electronics to a read/write head in a hard disk drive is provided. The interleaved conductor structure may allow for an increased characteristic-impedance range, greater interference shielding and a reduction of signal loss that is contributed by a lossy conductive substrate. The electrical traces may have different widths, be offset, or even wrap around each other at the via connections.

Abstract: A method and apparatus for generating a laser signal for driving a laser used in thermal-assisted recording. A channel of a hard drive generates a high-frequency component of the laser signal—e.g., a periodic wave or series of pulses—and synchronizes the phase of the laser signal with a corresponding write data signal which controls the magnetization of data bits within the magnetic disk of the hard drive. The channel may be connected to a read/write integrated circuit via a channel interconnect. The read/write circuit may include a second phase control to compensate for any phase shift and an adder circuit to combine the transmitted high-frequency laser with a DC bias. Further, the read/write circuit may include a feedback loop for adjusting the DC bias based on environmental parameters of the hard drive such as temperature.

Abstract: A method and apparatus for generating a laser signal for driving a laser used in thermal-assisted recording. A channel of a hard drive generates a high-frequency component of the laser signal—e.g., a periodic wave or series of pulses—and synchronizes the phase of the laser signal with a corresponding write data signal which controls the magnetization of data bits within the magnetic disk of the hard drive. The channel may be connected to a read/write integrated circuit via a channel interconnect. The read/write circuit may include a second phase control to compensate for any phase shift and an adder circuit to combine the transmitted high-frequency laser with a DC bias. Further, the read/write circuit may include a feedback loop for adjusting the DC bias based on environmental parameters of the hard drive such as temperature.

Abstract: An interleaved conductor structure for electrically connecting the read/write electronics to a read/write head in a hard disk drive is provided. The interleaved conductor structure may allow for an increased characteristic-impedance range, greater interference shielding and a reduction of signal loss that is contributed by a lossy conductive substrate. The electrical traces may have different widths, be offset, or even wrap around each other at the via connections.

Abstract: An interleaved conductor structure for electrically connecting the read/write electronics to a read/write head in a hard disk drive is provided. The interleaved conductor structure may allow for an increased characteristic-impedance range, greater interference shielding and a reduction of signal loss that is contributed by a lossy conductive substrate. The electrical traces may have different widths, be offset, or even wrap around each other at the via connections.

Abstract: An interleaved conductor structure for electrically connecting the read/write electronics to a read/write head in a hard disk drive is provided. The interleaved conductor structure may allow for an increased characteristic-impedance range, greater interference shielding and a reduction of signal loss that is contributed by a lossy conductive substrate. The electrical traces may have different widths, be offset, or even wrap around each other at the via connections.

Abstract: A system and method for effectively transferring electronic information in an electronic device may include a transmission line that connects a source device and a destination device. The foregoing transmission line may be implemented to include a conductor A and a conductor B for transferring the electronic information. One or more active termination circuits may coupled to conductor A and conductor B for being dynamically switched between a differential mode termination configuration and a single-ended mode termination configuration with respect to the transmission line. Control logic may be configured to dynamically place the active termination circuit into the foregoing differential mode termination configuration during a differential transmission mode. Alternately, the control logic may place the active termination circuit into the foregoing single-ended mode termination configuration during a single-ended transmission mode.

Abstract: A system and method for effectively transferring electronic information in an electronic device may include a transmission line that connects a source device and a destination device. The foregoing transmission line may be implemented to include a conductor A and a conductor B for transferring the electronic information. One or more active termination circuits may coupled to conductor A and conductor B for being dynamically switched between a differential mode termination configuration and a single-ended mode termination configuration with respect to the transmission line. Control logic may be configured to dynamically place the active termination circuit into the foregoing differential mode termination configuration during a differential transmission mode. Alternately, the control logic may place the active termination circuit into the foregoing single-ended mode termination configuration during a single-ended transmission mode.

Abstract: A low voltage amplifier with gain boosting and a reduced power supply voltage requirement. A cascode amplifier circuit, biased with the power supply voltage, amplifies a pair of related, differential input signals based upon a pair of gain boost control signals and in accordance therewith provides a pair of gain boosted signals which correspond to the input signals. A gain boost control circuit, also biased with the power supply voltage, uses the differential input signals to generate the gain boost control signals. A class AB amplifier circuit, also biased with the power supply voltage, amplifies the gain boosted signals and in accordance therewith provides a class AB output signal which corresponds to the original input signals. The cascode amplifier circuit, gain boost control circuit and class AB amplifier circuit together operate with a minimum power supply voltage which equals a sum of one active transistor input bias potential and two active transistor output bias potentials(V.sub.DD(min) -V.sub.SS =V.