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Class 360/68 - Recording amplifier


Subclass of Class 360 - Dynamic magnetic information storage or retrieval
Definition: Subject matter wherein the amplification is specifically
No. of patents: 424
Last issue date: 09/06/2011


1                      
NumberTitleIssue Date
8014098Technique for duty cycle shift in hard disk drive write system
A circuit for providing a write current having a programmably adjustable duty cycle in a hard disk drive write channel has a differential pair gain circuit for receiving a data input signal and generating a differential output voltage to provide a differential write...
09/06/2011
8009379Method, apparatus and program storage device for dynamically adjusting the write current in each head to compensate for variation in disk drive and environmental parameters
A method, apparatus and program storage device for dynamically adjusting the write current in each head to compensate for variation in disk drive and environmental parameters is disclosed. A current in the write head is dynamically adjusted to compensate for variati...
08/30/2011
7948703Adaptive target optimization methods and systems for noise whitening based viterbi detectors
Apparatuses and methods are provided for adaptively updating a target for a recording channel, such as a magnetic recording channel. In some embodiments, a read channel apparatus is provided which includes data path modules and adaptive path modules. The data path m...
05/24/2011
7944641Overshoot duration range selection in a hard disk drive
A hard disk drive that stores data on a disk. An overshoot duration is used to write data onto the disk. The value of the overshoot duration is a function of the data rate, which can vary for different areas of the disk. For example, the data rate can be higher at a...
05/17/2011
7933090Disk drive establishing write current limits prior to optimizing the write current for a plurality of tracks
A disk drive is disclosed comprising control circuitry operable to calibrate a write current parameter. A write current is initialized to an initial write current INIT_Iw, and an overshoot is initialized to a maximum MAX_OS. The write current is swept from INIT_Iw t...
04/26/2011
7881002Method of increasing recording density of hard disc drive and controlling device thereof
Provided is a method of increasing recording density and a control apparatus for increasing the recording density. The method includes applying a recording current corresponding to a recording signal to a magnetic head of a hard disc drive (HDD), and limiting a curr...
02/01/2011
7881003Write driver system for data storage systems
A write driver system includes a logic circuit including first switching devices which receive input write signals and generate control signals. A plurality of predriver circuits includes second switching devices and generates drive signals based on the control sign...
02/01/2011
7796355Reverse write current preshoot
Methods of generating a write current in response to a write command include generating a reverse preshoot write current having a polarity opposite to a polarity for generating a magnetic transition corresponding to the write command, and then generating a write cur...
09/14/2010
7746591Methods and apparatus to provide dynamically-biased write drivers for hard disk drive (HDD) application
Methods and apparatus to provide dynamically biased write drivers for hard disk drive applications are described. According to one example, a hard disk drive write system includes a drive signal generator to receive data to be written to a hard disk drive platter an...
06/29/2010
7729077Disk drive write driver and associated control logic circuitry
An H-bridge driver for a disk drive system includes first and second high side switched legs and first and second low side switched legs. An inductor head for writing data to and reading data from a magnetic media is connected to form a center of the H-bridge. The s...
06/01/2010
7701657High-density recording method for hard disk drives and a pre-amplifier circuit suitable for use with same
A magnetic recording method is provided where ternary data is recorded on a magnetic recording medium by forming a first area that corresponds to a first value of the data and in which a first magnetization state is continued at least during the minimum write width....
04/20/2010
7697227Hard disk drive
A hard disk drive includes a disk pack having at least one disk for recording and/or storing data and a spindle motor that support and rotates the disk, a base to which the disk pack is mounted, a cover that covers an upper surface of the base, and a respective filt...
04/13/2010
7679855Write transducer and system implementing same
A magnetic, head in one embodiment includes a substrate; a write transducer; leads coupled to the write transducer; and a resistor coupled between one of the leads and the substrate or a common line. A magnetic storage system in another embodiment includes a cable h...
03/16/2010
7667917Method and apparatus for controlling write parameter according to voltage variation
Provided is a method and an apparatus for controlling a write parameter according to a voltage variation. The method for controlling the write parameter includes monitoring a voltage supplied to a pre-amplifier before performing a write operation and adjusting the w...
02/23/2010
7660064Methods and apparatus for controlling write driver current
A hard disk drive write driver circuit is described that can change the output impedance of the write driver by use of a lookup table of control values. A control value is selected from the lookup table by using an address based on a dynamic system variable and a pr...
02/09/2010
7609470Information storage device, write current adjustment method for the information storage device, and write control circuit
There is provided a magnetic disk device or the like which is capable of improving signal quality by suppressing occurrence of erasure of adjacent tracks due to spreading of a writing spot. The magnetic disk device is capable of controlling a steady state value of a...
10/27/2009
7483230Write-current control chip and magnetic disk drive using the same
Embodiments of the present invention provide a write-current control chip capable of effectively preventing adjacent track interference (ATI) that occurs depending on how a magnetic disk drive is used, and to provide a magnetic disk drive using the write-current con...
01/27/2009
7466508Impedance-matched write circuit with shunted matching resistor
An impedance matched write circuit is provided that shunts one or more matching resistors. The impedance matched write circuit includes an interconnect for connecting to a write head and at least one resistor between a control voltage and the interconnect for impeda...
12/16/2008
7463442Impedance-matched write driver circuit and system using same
Embodiments of the present invention relate to an impedance-matched write driver circuit which comprises a voltage source, a write driver circuit electrically coupled to the voltage source, a signal input coupled so as to effect the output of the write driver circui...
12/09/2008
7453659Circuit and method for write current driver
System and method for write current drivers for inductive heads used in mass storage drives. A preferred embodiment comprises a write current circuit coupled to an inductive write head, a MOS transistor boost circuit and a matching circuit, both coupled to the write...
11/18/2008
7450329Method to vary symmetry and coupling in symmetrical write drivers for disk driver preamplifiers
The present invention achieves technical advantages as a preamplifier write driver (10) having a varying common-mode output voltage. This varying common-mode output voltage also adjusts the derivative of the common-mode voltage, which is proportional to the a...
11/11/2008
7417713Optical disc with a theft deterrent coating
An optical disc used for storing content includes a theft control area selected to render the disc unreadable. The disc must be exposed to radiation of a specific wavelength before it can be read by a regular device. The theft control area may include an area that c...
08/26/2008
7417817Write 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 includes a first driver circuit and a first feedback path between th...
08/26/2008
7417818Magnetic recording device
A magnetic recording device capable of reducing the size of a writing circuit and the power consumption by readily adjusting the overshoot of the write current pulses is provided. Two or more transmission lines having different characteristic impedances are provided...
08/26/2008
7411755Write driver system for data storage systems
A write driver system comprises first switching devices that generate gate drive signals. A write driver circuit includes second switching devices that are controlled by the gate drive signals. The second switching devices have higher voltage stress thresholds than ...
08/12/2008
7408313Low power preamplifier writer architecture
A circuit is adapted to activate a writer head of a data storage media drive during both the boost periods as well as the steady state periods. The current supplied to the writer head during the boost periods exceeds the steady state current and flows between positi...
08/05/2008
7405894Frequency, phase, and gain estimation technique for use in a read channel receiver of a hard disk drive
One or more methods and systems are presented for performing gain and timing acquisition of data read from one or more data sectors of a hard disk drive. The gain and timing information may be used to synchronize a read channel receiver of the hard disk drive to the...
07/29/2008
7375909Write 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 impedance of the write driver to the odd characteristic impedance of ...
05/20/2008
7373559Method and system for proactive drive replacement for high availability storage systems
Methods for preventing the failure of disk drives in storage systems are disclosed. A system and a computer program product for preventing the failure are also disclosed. Factors relating to the aging or early onset of errors in a disk drive are monitored. These fac...
05/13/2008
7372649Apparatus and method for applying write signals for driving a write head
An apparatus for use in applying write signals for driving a write head to effect writing information to a memory device; the write signals including a first write signal and a second write signal; includes: (a) a directing circuit receiving the write signals, direc...
05/13/2008
7372653Degauss waveform generator for perpendicular recording write head
Embodiments of the invention provide a hard disk drive that is capable of performing degaussing promptly and properly and a recording method for use with such a hard disk drive. A hard disk drive according to one embodiment of the present invention comprises a curre...
05/13/2008
7365928Write 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 impedance of the interconnect and a voltage boosting circuit. The voltage b...
04/29/2008
7362530Amplifier 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 signals received from the sensor; the first amplifying circuit segment inc...
04/22/2008
7355804Disk drive partially autonomous preamplifier for write current parameters
A disk drive includes a rotatable data storage disk, and head, a controller, and a preamplifier. The head is configured to write data to and read data from the disk. The controller is configured to generate a write current command. The preamplifier includes a plural...
04/08/2008
7355938Timing recovery method and storage apparatus for suppressing control of sampling positions
A timing recovery method samples, equalizes and detects a signal reproduced from a recording medium and to output a detection signal, controls sampling positions based on a phase error between the equalized signal and the detection signal, and obtains likelihood inf...
04/08/2008
7356102Gain compensation over temperature and frequency variations in wireless transceivers
Systems and methods are provided for controlling gain compensation over temperature and frequency variations. A variable amplifier may be used to receive a control signal and an input signal. The variable amplifier may be operable to apply a gain to the input signal...
04/08/2008
7342370Electronic control system with torque and/or speed boost for motor vehicle seats
A motor vehicle seat adjuster includes a DC motor and a control system operably connected to the motor to control seat motion to a desired motion profile. Power to the motor is variable from less than 100% of normal power to greater than 100% of normal power. The de...
03/11/2008
7339760Integrated 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 from write mode to read more to provide an output signal representative...
03/04/2008
7324301Striping data simultaneously across multiple platter surfaces
A hard disk drive comprises an actuator with independently movable arms and a printed circuit board with custom core electronic architecture. The drive also comprises one or more platters aggregating two or more platter surfaces whereupon data may be read from or wr...
01/29/2008
7315428Magnetic media write signal filter
In one embodiment, a magnetic media write signal filter includes a plurality of resistors connected in series across output signal lines of a write driver and a capacitor connected between a junction of resistors and a ground. ...
01/01/2008
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