Modern CMOS hall sensors with integrated magnetic concentrators

Abstract

Combining modern CMOS Hall sensors with integrated magnetic concentrators dramatically enhances magnetic field measurement performance. A first key feature is that one, two, or all three magnetic field components can be measured in a small spot. On-chip digital signal processing allows for the evaluation of the flux density vector direction instead of merely the flux density strength. By this principle very robust and thermally insensitive contact-less angular and linear position sensors can be made. The second key feature is the passive magnetic flux amplification of the integrated concentrator by up to one order of magnitude. This feature is particularly interesting for the measurement of low flux density as for example around a current carrying conductor. The combination of low-field amplification and multi-axis capability allows even to address applications like the electronic compass, which have up to now been considered as far too demanding for Hall sensors. © 2008 Springer-Verlag Berlin Heidelberg.