Magnetic field sensors, also known as magnetometers, are widely used in a number of applications including in, for example, compass, security, and military applications, geophysics and space research, biomagnetism and medical applications, and non-destructive testing. Magnetic field sensors are typically based on semiconductor materials (e.g., Hall sensors, magnetoresistors, and so forth) and ferromagnetic materials (e.g., ferromagnetic magnetoresistors and flux guides). Other magnetic field sensors utilize optical, resonant, and superconducting properties.
In many Earth's field magnetic sensing applications, especially those involving compassing or orientation, it is extremely desirable to have three-axis sensing capability. In order to achieve low cost of such sensors, it is also desirable that the solution be a single chip or even fully integrable onto the accompanying application specific integrated circuit (ASIC) die. In handheld and miniaturized applications it is also critical to minimize power consumption in order to extend battery life.