Horizontal hall effect sensor with high maximum absolute sensitivity

Abstract

The sensitivity of conventional Hall effect sensors is strongly limited by the well known short-circuit effects. Many researches were devoted to reduce offset and noise but few works were carried out to improve the sensitivity. Here, a new shape of integrated horizontal Hall effect device is presented. This particular shape has been developed in order to minimize the short-circuit effects in the sensor, allowing to reduce its length to width ratio and consequently to reduce its average resistance. Thus the biasing current of this sensor can be significantly increased in order to obtain a higher absolute sensitivity than for conventional devices. Such a Hall effect device needs a specific biasing circuit which is also presented, first in a simple version and second in an improved one. A resolution of ¡ £¢ ¥¤ §¦ has been reached on a bandwidth of © to © with a ¡ £ "! #¢ ¥¤ §$ % sensor biased with a current of ¢ "! & (' $ 0) , the corresponding absolute sensitivity being ¨$ 01 32 ¦ . The maximal absolute sensitivity of a so shaped device can be increased as much as needed by increasing its width-to-length ratio, without loss on the current related sensitivity.

An improved compact model of cross-shaped horizontal CMOS-integrated Hall-effect sensor

“…This effect has been widely explored and the equation linking Hall voltage and biasing current are well-known [8].…”

Compensation on Hall effect sensor of PWM switching control

“…From (3), it is clear that the measured voltage V H is proportional to the current i L [4]. Hence, the load current i L can be obtained if the voltage/ current ratio is given.…”

Compact modeling of offset sources in vertical hall-effect devices

“…It provides low-cost solutions for the measurement of a wide range of magnetic fields with a medium resolution [2]. The main applications of integrated Hall-effect devices are in the fields of automotive, contactless current sensors, and medical engineering [3].…”

“…For this kind of applications, the transducer (i.e. the Hall plate which transforms the magnetic field into a voltage) is integrated together with the power supply, the sensor conditioning circuit and the signal processing circuitry [2][3][4]. In this case, the use of EDA tools such as Cadence ® is mandatory to achieve an efficient design of the microsystem.…”