Seagate Technology Incorporated

Stefan Andrei Ionescu

Bruce Douglas Buch

Nurul Amin

Michael Thomas Johnson

Housan Dakroub

Zine Eddine Boutaghou

Jason Wayne Riddering

John Stuart Wright

Ladislav Rudolf Pust

Neal Frank Gunderson

Scott Edward Ryun

Andrew Robert Motzko

Richard Edward Martin

Subra Nagarajan

Subhash Guddati

Antanas Daugela

Rick Pfahl Freeman

Jesse Speckhard

CheeWee Cheng

Andy Chou

ShengYuan Lin

SweeChuan Samuel Gan

Erick J Lindquist

Transmission signals may generated based on three differential signals and transmitted along a channel. Each of the plurality of transmission signals may include a signal representative of each of the three differential signals. After receiving the transmission signals, the original three differential signals may be generated based on the transmission signals.

Channel apparatus for transmitting multiple differential signals

Systems and methods are included for determining a presence of an upcoming reading field during a write mode of a storage device, and initiating a read-while write RWW) mode of the storage device in response to the sensed reading field. Initiating the RWW mode comprises warming up the reader circuitry, generating a signal in response to an end to the write operation, and activating reader bias current in response to the generated signal.

Pin-efficient reader bias enable control

First and second read sensors are coupled in series to a preamplifier via respective first and second signal lines and a common signal line between the first and second read sensors. Independent first and second currents are supplied to the respective first and second read sensors. The first and second currents are varied to maintain respective first and second fixed bias values (e.g., fixed voltage or fixed current) on the first and second read sensors.

First and second read sensors coupled to a preamplifier via a common signal line

Systems and methods are included for determining a presence of an upcoming reading field during a write mode of a storage device, and initiating a read-while write (RWW) mode of the storage device in response to the sensed reading field. Initiating the RWW mode comprises warming up the reader circuitry, generating a signal in response to an end to the write operation, and activating reader bias current in response to the generated signal.

Apparatus and method for positional sensing and control. In accordance with some embodiments, a transducer is positioned adjacent a recording medium. The transducer includes a write element, a read element, a heater and a thermally responsive sensor. Power is applied to the heater to establish a selected fly height of the transducer relative to the medium. A contact event between the transducer and the medium is detected responsive to an accumulated plural count of pulses in a bias signal obtained from the thermally responsive sensor.

In situ sensor based contact detection

Approaches for determining the timing latency of a communication path are described. Some embodiments involve a method for testing timing latency. A signal is driven on a first data path and is returned through a second data path through a loop back element. The timing latency of at least a portion of the communication path that includes the first data path and the second data path is tested using the signal returned on the second data path. The gain of the second data path is adjusted to a test value during the testing of the timing latency.

Gain control for latency testing

Systems and/or methods for measuring latency in an electronic device such as, e.g., a storage device, may include coupling circuitry configured to capacitively couple an outbound or write data path to an inbound or read data path. A latency measurement signal may be driven on the write data path, the coupling circuitry may transmit at least a portion of the latency measurement signal from the write data path to the read data path, and the latency measurement signal may be sensed on the read data path to be used to determine communication path latency in the device.

Communication path latency measurement using capacitive coupling

A magnetic device includes a write element having a write element tip and a conductive coil for carrying a current to induce a first field from the write element. A conductor proximate the write element tip carries the current to generate a second field that augments the first field. A driver provides the current to the conductive coil and the conductor, and a circuit phase shifts the current through the conductor relative to the current through the conductive coil.

Wire-assisted magnetic write device with phase shifted current

A circuit includes a slider, a data storage medium and a contact detection circuit electrically coupled to the slider and to the data storage medium. The contact detection circuit is configured to sense an electrical current indicative of contact between the slider and the data storage medium and responsively provide a contact detection output. The electrical current is produced without the application of a separate voltage between the slider and the data storage medium.

Detecting contact between a slider and a data storage medium without a separate contact-detection voltage source

Apparatus and method for head-disc interface (HDI) modal response monitoring. A sensing element disposed on a rigid actuator arm is mechanically impedance matched to a head-disc interface (HDI) supported by the actuator arm to resonate at a predetermined frequency corresponding to at least one disturbance associated with the HDI.

Head-disc interface (HDI) modal response monitoring

The disclosure is related to detecting a fault condition of a transducer for reading and writing data to a data storage medium. The fault condition can be detected based on a potential difference between a reference voltage and a common mode of the transducer.

Monitoring transducer potential to detect an operating condition

A read/write preamplifier circuit is provided that includes a fault detecting circuit that detects when two or more read/write preamplifiers are concurrently selected for communicating with their associated data heads and means for notifying the drive controller of that condition. In one embodiment of the invention, the means for notifying the drive controller that two or more preamplifiers are concurrently selected includes a data storage register that is readable by the drive controller and that has a fault flag which is set when two or more preamplifiers are concurrently selected. Also, in one embodiment, the fault detecting circuit includes a fault-detect transistor that drives a predetermined current if the preamplifier is elected. The collectors of the fault-detect transistors of each preamplifier are electronically coupled to each other and to a sensing circuit that senses if the fault-detect transistors of two or more preamplifiers are concurrently driving the predetermined current. In addition, a disc drive which includes such a preamplifier circuit is provided.

Multiple devices selected fault feature for data integrity in disc drive applications

A method of writing data to a magnetic data storage medium is provided. A peak amount of write current is provided to the transducer, after which the amount of write current is reduced to a second amount of write current, lower than the peak amount. In one embodiment, the second amount of write current is then maintained at a steady state value. In one embodiment, the magnitude of the steady state value is greater than the magnitude of the critical current. In one embodiment the magnitude and duration of the peak write current for each transducer are stored in memory and retrieved when the corresponding transducer is selected. Also provided is a disc drive adapted to implement the aforementioned methods.

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Burnsville, MN, United States of America

Stefan Andrei Ionescu