Current biasing circuit to reduce MR common mode voltage jumping for MR resistance measurement
US7656601B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 19, 2007 |
| Grant date | Feb 2, 2010 |
| Priority date | — |
| Expiry date | Aug 1, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2005/0018
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A circuit for measuring resistance of a magnetoresistive head. First and second current biasing circuits are respectively coupled to opposite sides of the head. The first biasing circuit includes a first resistance, and the second biasing circuit includes a second resistance. First and second current mirrors are respectively coupled to the first and second biasing circuits. A current leg is coupled to the current mirrors. The current mirrors drive current in the resistances so that a first voltage across the first resistance is substantially equal and opposite to a second voltage across the second resistance. The biasing circuits bias current through the head such that a voltage on the first side of the head is close to the first voltage and a voltage on the second side of the head is close to the second voltage, so that the common mode voltage of the head will be close to zero.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.