Asymmetry correction for magneto-resistive heads
US7092180B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 1, 2004 |
| Grant date | Aug 15, 2006 |
| Priority date | — |
| Expiry date | Jul 14, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2005/0018
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An asymmetry-reducing circuit adapted to process an input signal having positive and negative pulses of different amplitudes and generate a corresponding balanced signal having positive and negative pulses of substantially uniform amplitudes. The asymmetry-reducing circuit balances the input signal by providing signal contributions corresponding to the second and third orders of the input signal. In a representative embodiment, the asymmetry-reducing circuit includes a differential amplifier and a plurality of arrayed MOS transistors connected to its inputs and outputs such that source-to-drain conductance of the transistors provides input and feedback resistances to the amplifier. A switch set selectively couples the fingers (gates) of the transistors to the input signal to modulate the source-to-drain conductance with said signal such that the input and feedback resistances change in a complementary manner. Advantageously, circuits of the invention can correct signal asymmetry within a relatively wide asymmetry range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.