Voice coil motor control circuit having alternative modes of operation and method of operation thereof
US6373650B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 20, 1998 |
| Grant date | Apr 16, 2002 |
| Priority date | — |
| Expiry date | Aug 20, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/54
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A voice coil motor control circuit provides control signals to a voice coil motor circuit drivel that is coupled to a voice coil motor. A current sensing resistor is coupled in series with the voice coil motor. The control circuit includes a sense amplifier having inputs that couple to the current sensing resistor and includes a feedback circuit that includes an input and also includes an output that couples to the voice coil motor driver. In a first mode of operation, the feedback circuit input is coupled to an output of the sense amplifier. The control circuit also includes an inverting operational amplifier. In the first mode of operation, the inverting operational amplifier is bypassed. In a second mode of operation corresponding to deployment of a read/write head from a parked position onto the disc, the inverting operational amplifier is coupled in series between the sense amplifier output and the feedback circuit input. As a result, a velocity of the voice coil motor is more precisely and accurately controlled.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.