Xuemin Yang from 2174 Anthony Dr, Campbell, CA 95008, age 51

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Optical Source Driver Circuit Having Overshoot Controller
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US Patent:

20130336663, Dec 19, 2013
Filed:

Jun 18, 2012
Appl. No.:

13/525982
Inventors:

Jason P. Brenden - Woodbury MN, US
Xuemin Yang - Edina MN, US
Cameron C. Rabe - Inver Grove Heights MN, US
Assignee:

LSI Corporation - Milpitas CA
International Classification:

H01S 3/10
G11B 13/04
H04B 10/04
G11B 7/126
US Classification:

398182, 369 5911, 369 1326, 372 19, G9B 7099, G9B 13002
Abstract:

A driver circuit configured to generate a drive signal for an optical source comprises an overshoot controller that provides an amount of overshoot for a given logic state of the drive signal as a function of a duration of at least one previous logic state of the drive signal. The drive signal may alternate between a first logic state associated with a first operating mode of the optical source and a second logic state associated with a second operating mode of the optical source. The overshoot controller may be configured to provide amounts of overshoot for respective instances of the first logic state that are proportional to the durations of their respective immediately preceding second logic states. The driver circuit may be implemented in a heat-assisted magnetic recording system in which the optical source alternates between on and off states associated with respective magnetic write and magnetic read modes.

Unipolar Current Driver
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US Patent:

8565048, Oct 22, 2013
Filed:

May 15, 2012
Appl. No.:

13/472448
Inventors:

Ross S. Wilson - Menlo Park CA, US
Jason P. Brenden - Woodbury MN, US
Xuemin Yang - Edina MN, US
Assignee:

LSI Corporation - Milpitas CA
International Classification:

G11B 11/00
H01S 3/00
US Classification:

369 1326, 369116, 372 3807
Abstract:

Various embodiments of the present invention provide single-ended and differential current drivers for heat assisted magnetic recording and other applications. For example, a current driver is disclosed that includes an upper output terminal and lower output terminal, a number of current switches operable to selectively contribute electrical currents through the upper and lower output terminals, a control input for each of the current switches operable to control the electrical currents, and a voltage supply operable to establish a voltage across the upper and output terminals.

Fly Height Control For Hard Disk Drives
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US Patent:

20140185158, Jul 3, 2014
Filed:

Dec 31, 2012
Appl. No.:

13/731693
Inventors:

- Milpitas CA, US
Xuemin Yang - Edina MN, US
Scott M. O'Brien - Eden Prairie MN, US
Assignee:

LSI Corporation - Milpitas CA
International Classification:

G11B 5/60
US Classification:

360 39
Abstract:

A fly height control circuit includes an input node to receive a digital control signal, an output node to output a control current to a resistive heater element to adjust a spacing between a read/write head and a surface of a storage medium, and control circuitry to process the digital control signal and generate the output control current based on the digital control signal. The control circuitry generates a first reference current based at least in part on the control current output from the output node. The control circuitry controls a slew rate of the first reference current to generate a slew rate controlled reference current. The control circuitry generates a second reference current based on a feedback voltage at the output node. The control circuitry compares the slew rate controlled reference current with the second reference current to adjust the control current output from the output node.

Xuemin Yang