Read head preamplifier with thermal asperity transient control
US7274523B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 31, 2004 |
| Grant date | Sep 25, 2007 |
| Priority date | — |
| Expiry date | Jun 11, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2005/0016
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A preamplifier for correcting for thermal asperity transients in disk drives using magneto resistive read heads. The preamplifier has an input gain stage receiving a signal from the read head and an output buffer outputting a reader output to a read channel that is filtered of thermal asperity transients by a high pass filter positioned between the input gain stage and the output buffer. The high pass filter is voltage controlled based on an input control signal from a filter controller. The filter controller uses a low pass filter functioning as a peak detector to detect peaks in either the input or output voltage of the high pass filter. The low pass filter output is applied to a non-linear function generator generating the control signal for the high pass filter based on an increasing function of the absolute value of the low pass filter output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.