Not-plate-like Hall magnetic sensors and their applications

Abstract

This paper is a survey of a new class of Hall devices which are not plate-like but have three-dimensional structures. The survey covers: the vertical Hall device, sensitive to a magnetic field parallel with the chip surface; the cylindrical Hall device, which behaves as a vertical Hall device combined with magnetic flux concentrators; the two-axis vertical Hall device, for the two in-chip-plane components of a magnetic field; and the three-axis Hall device, to measure all three components of a magnetic field. All these Hall magnetic sensors are fabricated using the “vertical Hall” silicon process and feature low supply current, low noise, and high long-term stability. Their applications include: high-accuracy magnetometry, long-range position sensing, angular position sensing, current sensing, magnetic scanning of documents, and more.