Disk drive employing method of unlatching actuator arm using VCM voltage limiting circuit to limit actuator arm velocity

摘要

A disk drive employs a method of unlatching an actuator arm from a latch restraining the actuator arm in a disk drive. The disk drive includes a first node, a second node, and a voice coil motor (VCM) coupled to the actuator arm. The VCM includes a coil connected between the first node and the second node. The method includes applying a voltage between the first node and the second node to cause current to flow through the coil in order to move the actuator arm away from the latch at a variable actuator arm velocity. The method includes temporarily activating a VCM velocity control signal to enable a VCM voltage limiting circuit connected in parallel with the coil between the first node and the second node. The method further includes limiting the voltage applied across the coil to a predetermined VCM voltage level with the enabled VCM voltage limiting circuit in order to limit the actuator arm velocity.