AS5130ATST AMSCO [austriamicrosystems AG], AS5130ATST Datasheet - Page 34

• Manufacturer Part Number: AS5130ATST
• Description: 8 Bit Programmable Magnetic Rotary Encoder with Motion Detection & Multiturn
• Manufacturer: AMSCO [austriamicrosystems AG]

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 30. B
Figure 30
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 B
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 B
amplitude becomes nonlinear, which results in larger errors that mainly affect the accuracy of the system
32).
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3.5
shows a cross sectional view of the vertical magnetic field component Bz between the north and south pole
z
Field Distribution Along the X-axis of a 6mmØ Diametric Magnetized Magnet
2.5
N
1.5
z
follows a fairly linear pattern up to about 1.5mm radius. Consequently, even if
Bz; 6mm magnet @y=0; z=1mm
X-displacement [mm]
0.5
Revision 1.00
0
0.0015
0.001
0.0005
-0.0005
-0.001
-0.0015
-0.5
-1.5
-2.5
S
(see Figure
-3.5
34 - 41
z