Disk drive comprising spin down circuitry having a current limit circuit for enhancing power and braking control
US6549359B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 2000 |
| Grant date | Apr 15, 2003 |
| Priority date | — |
| Expiry date | Jul 25, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/54
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A disk drive is disclosed comprising a disk, a head actuated radially over the disk, and 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. A plurality of switching elements are coupled to the windings, and switch control logic generates 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. A signal generator generates 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. A plurality of current detectors is provided, wherein each current detector for measuring a current flowing through a respective one of the switching elements. A current limit circuit generates a control signal which prevents the periodic signal f…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.