Disk drive comprising an offset-nulling amplifier for detecting a back EMF voltage of a voice coil motor
US6900959B1 · kind B1 · utility
115Cited by
4References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 31, 2003 |
| Grant date | May 31, 2005 |
| Priority date | — |
| Expiry date | Sep 9, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/5547
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A disk drive is disclosed employing an offset-nulling amplifier for detecting a back EMF voltage of a voice coil motor (VCM) in a velocity mode servo control system. The offset-nulling amplifier comprises a differential amplifier, an input stage for swapping the polarity of the input voltage at a periodic interval, and an output stage comprising a single-ended amplifier having an input switched at the periodic interval between the positive and negative outputs of the differential amplifier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.