Patent ID: 6577465
Filing Date: 2003-06-10
Classification: G11B

Abstract:
A disk drive comprising:(a) a disk; (b) a head actuated radially over the disk; (c) a spindle motor for rotating the disk, the spindle motor comprising a plurality of windings and a rotor rotatable at a variable spin rate, wherein the rotor generates a back EMF (BEMF) voltage across the windings proportional to the spin rate of the rotor; (d) a plurality of switching elements coupled to the windings; (e) switch control logic for generating switch control signals applied to the switching elements for commutating the spindle motor during normal operation and for generating an internal supply voltage from the BEMF during a spin down mode, the internal supply voltage for parking the head; (f) a programmable signal generator for generating a periodic signal, the periodic signal for periodically grounding the windings during the spin down mode in order to boost the internal supply voltage, wherein grounding the windings applies a braking torque to the spindle motor; and (g) a programmable register for storing a digital value for adjusting a frequency characteristic of the periodic signal, thereby enhancing power management.