Write precompensation with frequency synthesizer
US5325241A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 14, 1991 |
| Grant date | Jun 28, 1994 |
| Priority date | — |
| Expiry date | Jun 14, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/1258
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A write precompensation circuit employs a frequency synthesizer for providing a variable timing signal linked to variable transfer rate in a track zone recording system of a disk drive. The synthesizer also provides an operating frequency current sense signal that is used to generate bit shift of data bits being recorded. A ramp voltage on a ramp capacitor and a logic signal from a bit shift decision circuit are determinative of the magnitude and direction of bit shift, early or late. The VCO and its capacitor are formed on the same IC chip as the ramp capacitor thereby minimizing mismatch due to tolerances inherent in production and operation of electrical components.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.