Single-chip two-axis magnetic field sensor
US9575143B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 23, 2012 |
| Grant date | Feb 21, 2017 |
| Priority date | — |
| Expiry date | Nov 6, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/098
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention discloses a design for a single-chip dual-axis magnetic field sensor, based on magnetic tunnel junction (MTJ) elements and permanent magnets integrated on a semiconductor substrate to produce two types of sensor bridges that detect orthogonal magnetic field components. The orthogonal magnetic field component detection capability results from the different types of sensor bridges that can be produced by varying the shape of the MTJ elements and the bias fields that can be created by permanent magnets. Because the permanent magnets can create orthogonal bias fields on the different sensor bridges, it is possible to use a single pinned layer to set direction for both sensor bridges. This is advantageous because it permits the two-axis sensor to be fabricated on a single semiconductor chip without the need for specialized processing technology such as local heating, or deposition of multiple magnetoresistive films with different pinned layers setting directions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.