Other

Stmicroelectronics Gmbh

Gilles Denoyer

Roberto Alini

Tehri S Lee

Axel Alegre De La Soujeole

Xiaokun L Chew

Giuseppe Patti

Mark R McCornack

Quocdzung T Lam

Su Dang Le

David Joseph Bezinque

A method is disclosed for controlling the write head of a magnetic disk storage device. The method includes sinking current from the first terminal of the write head and sourcing current to the second terminal of the write head substantially simultaneously with sinking current from the first terminal so that a first steady state voltage level appears on the first terminal of the write head and a second steady state voltage level appears on the second terminal thereof that are approximately at a midpoint between a high reference voltage level and a low reference voltage level. The common mode voltage of the write head is substantially constant over time.

Method for differentially writing to a memory disk

An apparatus (and method) is provided that reduces thermal interference in the read signal of a disk drive. A variable or programmable resistance is used to change the transfer function of a filter in the read channel of the disk drive to filter the read signal. The filter has a first transfer function (first cut-off frequency) related to the programmed resistance during normal operation of the disk drive (i.e. when thermal interference is not detected). When thermal interference is detected in the read signal, the resistance is programmed to another value resulting in the filter having a second transfer function (second cut-off frequency). The resistance element includes a transconductance amplifier whose transconductance is variable or programmable to different values resulting in different programmable transfer functions (or one of a multitude of cut-off frequencies) for the filter. In the preferred embodiment, detection of thermal interference increases the cut-off frequency of the filter thereby filtering, or reducing the effects of, the thermal interference in the read signal.

Apparatus and method for reducing thermal interference in MR heads in disk drives

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Campbell, CA, United States of America

Gilles Denoyer