Monolithic magnetic Hall sensor using dynamic quadrature offset cancellation

Abstract

The offset voltage and its temperature drift and production spread, which generally degrades the zero-level stability and reproducibility of magnetic Hall sensors, can be reduced using a single Hall plate and switching means for periodic permutation of the supply and output contact pairs. The present work describes a chopper-based 5-V monolithic linear Hall sensor with a /spl plusmn/0.1 T full scale where this dynamic plate offset cancellation technique has been employed together with a cost-effective signal conditioner. The device was integrated using a 2-/spl mu/m conventional BiCMOS process and the final chip, measuring 15/spl times/1.5 mm/sup 2/, shows, after packaging in a 3-pin plastic package, a residual offset with a production spread and a temperature-induced drift five to ten times smaller than in currently used multiplate dc quadrature cancellation approaches. The device does not require external components and provides an output free of HF residues.