Seagate Technology Incorporated

KarWei Koay

David L Schell

Robert A Alt

John Charles Purkett

Brent Jay Harmer

LingZhi Yang

SangHoon Lee

Apparatus and method for mitigating impedance changes in a microactuator conductive joint. In accordance with some embodiments, a microactuating element has a conductive input junction, the junction having dissimilar metals in contact with one another. The microactuating element is adapted to mechanically deform to displace a control object responsive to a micractuation control signal that is applied to the junction. A control circuit applies a bi-directional transition signal to the conductive input junction to reduce an increased impedance of the junction.

Impedance mitigation of a microactuator conductive joint

Apparatuses and methods are disclosed that relate to movement of actuator arms from a stopped position. In one example, a method may include attempting to unlatch an actuator arm from a stop and measuring an electrical parameter of a driver circuit of the actuator arm. The method may further include detecting an unsafe unlatch event using a controller when the electrical parameter does not exceed a first threshold within a predetermined period of time.

Actuator arm unlatching

A Bemf detect circuit is configured for modeling Bemf error via calculation of time correlations associated with two or more different non-calibrated sense resistor gain values to derive a calibrated sense resistor gain value. A method is provided for calibrating a Bemf detector circuit by setting a sense resistor gain to a plurality of different gain values, observing Bemf sample values for each of the gain values, and deriving a calibrated gain value by non-iteratively modeling the relationship between the gain values and the associated Bemf sample values.

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Erie, CO, United States of America

KarWei Koay