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7626777 Variable threshold bipolar signal peak detector  
A method and apparatus for detecting signal peaks caused by a thermal asperity event in a magnetic recording media to reduce data reading errors introduced by the thermal asperity event. A common...
7605993 Write current boosted head amplifier  
Embodiments in accordance with the present invention provide a disk drive and a control method in the disk drive which can obtain good recording performance by amplifying the write current...
7602578 Servo writer and servo writing process  
A servo writer according to the present invention is a servo writer which writes a servo signal on a servo band of a magnetic tape. It comprises a magnetic tape driving system in which a magnetic...
7561358 Multi-register read channel optimization  
A method for optimizing read/write channel parameters of a hard disk drive. The process includes measuring a first bit error rate of a head using an initial set of read/write channel parameters and...
7558014 Programmable high pass amplifier for perpendicular recording systems  
A high pass amplifier comprises a first amplifier including an input and an output. A second amplifier includes an input that communicates with the output of the first amplifier and an output. A...
7551384 Systems and methods for calibrating a read/write channel of a hard disk drive  
A read/write channel for a hard disk drive comprising at least one analog read component and a fly height control system. The fly height control system controls fly height based on a current fly...
7551383 Adjusting voltage delivered to disk drive circuitry based on a selected zone  
A disk drive includes a disk comprising a plurality of zones, a clock for generating a timing signal having a timing frequency, a voltage controller for providing a supply voltage, and circuitry...
7545594 Method and system for removing signal defects in MR head signals  
The disclosure describes a data storage system that includes a signal defect correction system for removing signal defects in magnetoresistive head playback signals. The signal defect correction...
7532427 TMR/GMR amplifier with input current compensation  
An amplifier system with feedback current cancellation comprises an amplifier with at least one stage, a feedback network, first and second replica circuits, a buffer, second and third resistances,...
7522368 Differential voice coil motor control  
A disk drive controller including a differential voice coil motor control function is disclosed. The differential voice coil motor control function includes an on-chip compensation network for the...
7518813 Methods and structure for detecting anomalous events in a disk drive using VGA variance  
Methods and structures for detecting touchdown of the read/write head on its recording surface or for detecting other read signal amplitude modulations as proportional to variance of the value of...
7515371 Channel postamble extension to de-gauss pole tips  
A technique for de-gaussing the pole tips and yoke of a write transducer in a perpendicular magnetic recording system is provided. An oscillator in the read channel is configured to produce an...
7508617 Fly height compensation using read gain control loop  
Apparatus and methods are disclosed that regulate head fly height so as to compensate for variation in height of a disk surface. An exemplary apparatus includes a circuit that detects disk height...
7508613 Method and apparatus for balanced shield shunts, leads and pads for electrical noise reduction in read heads  
A symmetrical read element circuit for reducing electrical and magnetic noise using signal processing, such as a differential preamplifier. The circuits are symmetrically created on both sides of...
7495854 Dynamic method for asymmetry compensation in a storage read channel  
Provided is a dynamic method for asymmetry compensation in a storage read channel. An asymmetry cancellation component in communication with an analog-to-digital converter receives an analog signal...
7471491 Magnetic sensor having a frequency filter coupled to an output of a magnetoresistance element  
A magnetic sensor includes a magnetoresistance element having a peak of a thermal fluctuation strength of magnetization under a magnetic field having a certain frequency, a frequency filter...
7466200 Composite output stage for hard disk drive preamplifier  
An apparatus for supplying a load current. The apparatus comprises a first differential amplifier producing a differential output signal and an output buffer comprising a first and a second...
7463443 Reduced hardware control circuit device, with current loop for broad band hard disk drive applications  
A reduced hardware control circuit device includes a current loop for broad band Hard Disk Drive applications. The current loop detects the value of the current flowing on the coils of a voice coil...
7460324 Head amplifier circuit with function for degaussing residual magnetism of recording head  
In a data-recording mode, a driver circuit supplies a recording head with a recording current corresponding to write data. In a degaussing mode, the driver circuit supplies the recording head with...
7457067 Method of controlling a recording current, and magnetic disk device  
Embodiments of the invention make it possible to conduct stable recording on a magnetic disk, even in case of changes in flying height due to thermal protrusion. In one embodiment, a compensatory...
7417817 Write driver circuit for magnetic data storage systems  
A write driver circuit for a magnetic storage medium includes a first write driver sub-circuit that has an output that communicates with a first node of a write head. The first write driver circuit...
7394605 Broadband transmission path apparatus, suspension assembly and storage medium apparatus  
A broadband transmission path apparatus connects a head IC and a head in a suspension. Either one of the head IC and the head is assumed as a transmission terminal and the other is assumed as a...
7375909 Write driver with power optimization and interconnect impedance matching  
A write driver for driving a write current through a write head connected to the write head by an interconnect or flexible transmission line. The write driver includes a circuit matching an output...
7365928 Write driver with improved boosting circuit and interconnect impedance matching  
A write driver driving a write current through a head connected to the write head by an interconnect. The write driver includes a circuit matching output resistance to the odd characteristic...
7362530 Amplifier apparatus for use with a sensor  
An amplifier apparatus for use with a sensor includes: (a) a first and a second amplifying circuit segment coupled with the sensor and cooperating to effect substantially balanced handling of...
7339760 Integrated bias and offset recovery amplifier  
A preamplifier circuit is connected to a transducing head, and has integrated bias circuitry and offset recovery circuitry. The offset recovery circuitry is activated in response to a transition...
7327103 Driver and method for control of voice coil motor in disk drive  
A driver for a voice coil motor in a disk drive includes a sensor that provides a sense current by sensing a coil current in the voice coil motor, a comparator that provides an error current by...
7301715 Preamplifier fly height control (FHC) driver and sensing circuit  
Managing temperature of a read/write head ( 120 ) in a disk drive system in which there is a power variance due to different operation modes. A circuit device ( 100 ) determines and delivers...
7271968 Head protection circuit of hard disk drive  
A head protection circuit that protects a write head and a magnetoresistive (MR) read head by bypassing electrostatic charge applied to the write head when the power of a preamplifier is turned...
7265926 High speed hard disk drive with symmetric writer  
A disk drive data storage system, comprising a magnetic disk a head for writing data to the disk, and circuitry for providing a first voltage (HWX) to a first node (N 1 ) and a second voltage (HWY)...
7256954 Adaptive equalizer  
An adaptive equalizer comprising a variable filter which equalizes a digital input signal which is input in a time sequential order, an adaptive controller unit which updates a filter coefficient...
7242545 Asymmetric compensation circuit  
An apparatus, method, and system for providing asymmetric signal correction in a HDD system using magneto-resistive (MR) heads for reading information stored thereon. The MR head produces a signal...
7239467 Storage media reading writing system  
The storage media recording/writing system includes a media drive circuit, a head retaining means, a head moving means, a head drive circuit, a signal processing circuit, and a controller to...
7227709 System and method for providing head amplitude characterization  
To calibrate the VGA of a read head, test signals from a DAC are input to the VGA and the output of the VGA is observed, with the gain of the VGA being adjusted as appropriate. So that the DAC need...
7209307 Variable read output impedance control circuit for a magnetic media storage system  
A variable read output impedance control circuit of the present invention includes a variable impedance circuit as the output impedance of a magnetic media storage system. Preferably, the variable...
7206155 High-speed, low power preamplifier write driver  
A write driver circuit ( 38 ) uses a matching resistors (R 0 , R 1 ) to match the impedance of the head ( 32 ) disposed between output nodes (OUTP, OUTN). Control circuitry (Q 4 , Q 5 , Q 6 , Q 7 ,...
7199956 Disk drive self-servo writing using fundamental and higher harmonics of a printed reference pattern  
Disk drive self-servo writing includes transferring a reference pattern by magnetic printing onto a reference disk, wherein the resulting printed reference pattern includes embedded servo...
7190541 Hi-speed preamplifier write driver for hard drive with improved symmetry  
A write driver ( 38 ) produces balanced voltages across head ( 32 ) by using the input write data (WDX and WDY) drive transistors of a slower transistor type (typically PNP) on one half of an...
7177107 Preamplifier circuit with signal interference cancellation suitable for use in magnetic storage devices  
In one illustrative example disclosed, a magnetic storage device includes at least one magnetic disk; a magnetic head which includes first and second read sensors; a suspension which supports the...
7173786 Magnetic disk drive apparatus and method for compensating characteristics of magnetic disk drive apparatus  
A magnetic disk drive apparatus includes a magnetic disk with a data region, a magnetic head located in a region of the magnetic disk other than the data region or outside of the magnetic disk...
7167331 Electrostatic discharge protection circuit for magneto-resistive read elements  
A magnetic storage system includes a read element including a tunneling giant magneto-resistive (TGMR) sensor. A shunting device includes a control terminal and first and second terminals that...
7133233 Disk drive with read while write capability  
A disk drive includes recording media having one or more recording surfaces, one or more transducer heads positionable relative to the recording surfaces by an actuator operating within a head...
7130143 Apparatus, system, and method for measuring magnetoresistive head resistance  
An apparatus, system, and method are disclosed for measuring magnetoresistive head assembly resistance. A measurement module measures a reference voltage across a reference resistance while...
7126774 Magnetic recording and reproducing apparatus  
A magnetic recording and reproducing apparatus includes a separator and first and second amplifiers. The separator separates a servo data signal and a user data signal, both reproduced by a...
7119977 Reduced recovery time for perpendicular recording systems  
User data is read from a medium having servo data and user data encoded thereon. The user data is read with a read/write head that is operable in a write mode and a read mode. Servo data is read in...
7110204 Process-insensitive write current generation for a HDD preamplifier writer equipped with parallel output resistive damping  
The present invention achieves technical advantages as an improved Parallel Damping scheme suitable for very-low-supply preamp operation. The improved Parallel Damping Scheme accurately generates a...
7106536 Write head demagnetizer  
A demagnetizer for an inductive load having a driver circuit including at least one transistor and a ramp-down voltage source switchably connected to the driver circuit, so that when the ramp-down...
7099098 Preamplifier circuit and method for a disk drive device  
An amplifying circuit and method are disclosed for amplifying electrical signals, such as electrical signals generated by the read head of a disk drive. The circuit includes a pair of cross-coupled...
7088537 Removing residual magnetization in a data transducer  
Method and apparatus for removing residual magnetization in a data transducer, such as a recording head used to write data to a recording medium in a data storage device. A residual magnetization...
7085089 System and method for reducing circumferential transition incoherence in servowriting operations and magnetic disk drive incorporating the same  
For use with a servowriter that includes a writer core having a plurality of transistors that route servowriting current in response to a servo write signal, a write transition controller, a method...