Seagate Technology Incorporated

Maxtor Corporation

Jason Wolfson

Mourad Benakli

Albert John Wallash

Richard E Olsen

Ferruh Gocemen

Ahmet Kaya

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 current to effect the magnetic transition corresponding to the write command. The write current may be used for writing data to a storage disk of a disk drive that includes a write head configured to apply a magnetic field to the storage disk responsive to write currents. A preamplifier circuit includes a write current generator configured to receive a write current command and configured to generate, responsive to the write current command, a reverse preshoot current having a first polarity that is opposite a second polarity for generating a magnetic transition corresponding to the write command.

Reverse write current preshoot

A method for preventing electrical overstress from interfering with a magnetic read-write device by identifying one or more characteristic functions of the device that characterize electrical overstress, generating a wave form representative of the electrical overstress by using the one or more characteristic functions and enabling the generated wave form to be combined with a read signal to counteract the electrical overstress. The method can be implemented with a crosstalk cancellation circuit that includes a coupler filter configured to receive signals from the write driver, a differentiator to differentiate the signal, a gain adjust coupled to the coupler filter configured to adjust gain on the received signal, a phase adjust configured to adjust the phase to match the crosstalk, and an inverter coupled to invert the matched signal to enable cancellation of the crosstalk. The cancellation circuit can include two components, a first component that addresses common mode crosstalk and a second component that addresses differential mode crosstalk. The combination is added and inverted to enable cancellation of crosstalk in read components of a device.

Method for active cancellation of write-to-read crosstalk

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Shrewsbury, MA, United States of America

Jason Wolfson