AS5130ASST datasheet(33/40 Pages) AMSCO

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AS5130

Data Sheet - A p p l i c a t i o n I n f o r m a t i o n

Figure 27. Bz Field Distribution Along the X-axis of a 6mmØ Diametric Magnetized Magnet

Figure 27 shows a cross sectional view of the vertical magnetic field component Bz between the north and south pole

of a 6mm diameter magnet, measured at a vertical distance of 1mm. The poles of the magnet (maximum level) are

about 2.8mm from the magnet center, which is almost at the outer magnet edges. The magnetic field reaches a peak

amplitude of ~+/-106mT at the poles. The Hall elements are located at a radius of 1mm (indicated as squares at the

bottom of the graph). Due to the side view, the two Hall elements at the Y-axis are overlapping at X=0mm, therefore

only 3 Hall elements are shown. At 1mm radius, the peak amplitude is ~+/-46mT, respectively a differential amplitude

of 92mT. The vertical magnetic field Bz follows a fairly linear pattern up to about 1.5mm radius. Consequently, even if

the magnet is not perfectly centered, the differential amplitude will be the same as for a centered magnet.

For example, if the magnet is misaligned in X-axis by -0.5mm, the two X-Hall sensors will measure 70mT (@x= -

1.5mm) and -22mt (@x= -0.5mm). Again, the differential amplitude is 92mT. At larger displacements however, the Bz

amplitude becomes nonlinear, which results in larger errors that mainly affect the accuracy of the system (see Figure

29).

Bz; 6mm magnet @y=0; z=1mm

-0.0015

-0.001

-0.0005

0.0005

0.001

0.0015

-3.5

-2.5

-1.5

-0.5

0.5

1.5

2.5

3.5

X-displacement [mm]

AS5130ASST Fiches technique(PDF) 33 Page - ams AG