Avago Technologies General IP (singapore) Pte. Ltd.

Scott O'Brien

Ross Wilson

Jeffrey A Gleason

Jaydip Bhaumik

Jason P Brenden

David Fitzgerald

Bruce Alexander Wilson

Travis Roger Oenning

Cameron Carroll Rabe

Peter John Windler

Michael Straub

Andrew Krebs

Greg Starr

A circuit includes a light source, a sensor, and a switch. The sensor measures output of the light source and provides an electrical signal to a feedback loop that is indicative of the measured output of the light source. The switch is positioned in the feedback loop and is movable between a first position and a second position depending upon whether the feedback loop is operating in a first mode of operation or a second mode of operation. During the first mode of operation the output of the feedback loop adjusts at least one operating parameter of the light source responsive to the electrical signal. During the second mode of operation the output of the feedback loop does not adjust the at least one operating parameter of the light source responsive to the electrical signal.

Methods and devices for power control of a light source of a memory system

An apparatus for microwave-assisted magnetic recording includes a magnetic write head operable to write data to a magnetic storage medium. The apparatus includes a spin-torque microwave oscillator coupled to the magnetic write head and operable to provide microwave radiation to the magnetic storage medium. The apparatus includes a driver circuit in communication with the magnetic write head. The driver circuit is operable to dynamically modulate bias current provided to the spin-torque microwave oscillator in sympathy with data being written to the magnetic storage medium by the magnetic write head.

Methods and devices for spin torque oscillator control and monitoring

A storage system includes a magnetic write head, a magnetic storage medium, a channel circuit comprising a write data output, wherein the channel circuit is operable to process write data to be recorded on the magnetic storage medium by the magnetic write head, and a preamplifier operable to receive the write data from the channel circuit, wherein the preamplifier comprises a number of register pages configured to store pattern dependent write current characteristics for a variety of magnet lengths, and wherein the preamplifier is operable to retrieve the write current characteristics based on magnet lengths and to record data bits on the magnetic storage medium using the write current characteristics.

Magnetic recording system using pattern dependent writer having register pages for storing write currents

An apparatus for two-dimensional magnetic recording includes a storage medium, an array of magnetoresistive read heads disposed adjacent the storage medium and spaced to read a data track, a number of leads connected to the array of magnetoresistive read heads, and number of bias circuits connected to the array of read heads by the leads. The bias circuits can be configured to independently bias each of the array of read heads with the array of read heads connected in series or in parallel.

Magnetoresistive reader for two-dimensional magnetic recording

An apparatus for two-dimensional magnetic recording includes an array reader with a number of magnetoresistive read sensors configured to read data from a storage medium. The magnetoresistive read sensors have a number of connection terminals, with at least one of the connection terminals being shared by more than one of the magnetoresistive read sensors. The apparatus also includes a number of low-noise amplifiers connected to the connection terminals, each configured to amplify a differential signal from a different one of the magnetoresistive read sensors. The apparatus also includes a number of impedance balancing networks connected to a subset of the connection terminals.

Preamplifier common-mode noise rejection for two-dimensional magnetic recording

An apparatus for correcting crosstalk in an array reader magnetic recording system includes an array reader comprising a number of read heads operable to read data from a magnetic storage medium, a preamplifier configured to amplify the signals from the read heads, and a crosstalk correction circuit configured to reduce crosstalk between signals from the read heads.

Preamplifier crosstalk correction in array reader magnetic recording system

An apparatus for two-dimensional magnetic recording includes a storage medium, an array of magnetoresistive read heads disposed adjacent the storage medium and spaced to read a data track, wherein the array of magnetoresistive read heads share a common terminal, a number of leads connected to the array of magnetoresistive read heads, with one lead for each of the magnetoresistive read heads, plus a common lead connected to the common terminal, wherein each of the plurality of leads other than the at least one common lead are referenced to the at least one common lead, and a preamplifier connected to the array of magnetoresistive read heads by the plurality of leads and operable to perform pseudo-differential sensing or single-ended sensing of signals from the array of magnetoresistive read heads.

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Mendota Heights, MN, United States of America

Scott O'Brien