Fluxgate ASIC locates position within±2°

-- EDN, 4/13/2000

American Microsystems Inc and Precision Navigation Inc have collaborated in the development of a magnetic-sensing ASIC, which the companies claim is the first commercially available improvement of fluxgate technology in 100 years.

Using AMI's submicron mixed-signal process, the ICs can locate position to within ±2°. The ASIC is purportedly more sensitive than both the traditional fluxgate sensor and the experimental giant-magnetoresistive (GMR) units that have still not reached commercial production. The ASIC (picture) is basically a magnetometer, a magnetic sensor that detects both field strength and direction. AMI's design gathers 16 bits of heading information for each of its two standard coils. You can add a third coil to achieve full 3-D capability. On-chip digital processing eliminates all offsets and magnetic noise. To obtain different ranges, you can adjust the sensitivity of the circuit with digital registers. The ASIC connects to a special set of nonlinear coils that change inductance with small changes in the magnetic field. The magnetic-sensor ASIC is available for licensing from Precision Navigation Inc.

Precision Navigation Inc, 1 - 707-566-2260, www.precision nav.com.

American Microsystems Inc, 1-208-233-4690, www.amis.com.

-by Bill Travis