Smart Sensor Systems

9

Integrated Hall Magnetic Sensors

Radivoje S. Popović Pavel Kejik

9.1 Introduction

This chapter deals with integrated magnetic sensors whose principle of operation is based on the Hall effect. The Hall effect is one of the physical effects arising in matter carrying an electric current in the presence of a magnetic field. The effect is named after the American physicist Edwin H. Hall, who discovered it in 1879 [1, 2]. A brief introduction into the Hall effect is given in Section 9.2 of this chapter. A detailed treatment of the Hall effect and the related magnetic sensors can be found in the monograph [3].

The first Hall effect magnetic sensors became commercially available in the mid-1950s, a few years after the discovery of high-mobility compound semiconductors. Since then, the development of Hall effect devices has taken advantage of using high-quality materials and sophisticated, highly productive fabrication methods available in the microelectronics industry.

Today, Hall effect magnetic sensors form the basis of a mature and important industrial activity. They are mostly used as key elements in contactless sensors for linear position, angular position, velocity, rotation, electrical current, end so on. More that 2 billion Hall magnetic sensors were sold worldwide in the year 2000 [4]. In 2003, the global market of Hall magnetic sensors was about $600 million [5]. Most of currently produced Hall magnetic sensors are discrete elements; but the sales of discrete Hall elements ...