Simulation Modelling
Figure 43:
Arrangement of Hall Sensor Array on Chip (principle)
AS5040− SimulationModelling
Page 42
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With reference to Figure 43, a diametrically magnetized
permanent magnet is placed above or below the surface of the
AS5040. The chip uses an array of Hall sensors to sample the
vertical vector of a magnetic field distributed across the device
package surface. The area of magnetic sensitivity is a circular
locus of 1.1mm radius with respect to the center of the die. The
Hall sensors in the area of magnetic sensitivity are grouped and
configured such that orthogonally related components of the
magnetic fields are sampled differentially.
The differential signal Y1-Y2 will give a sine vector of the
magnetic field. The differential signal X1-X2 will give an
orthogonally related cosine vector of the magnetic field.
The angular displacement (θ) of the magnetic source with
reference to the Hall sensor array may then be modelled by:
(EQ4)
θ
=
arc
tan
(---Y-----1----–-----Y----2----)
(X1 – X2)
±
0.5°
The ±0.5° angular error assumes a magnet optimally aligned
over the center of the die and is a result of gain mismatch errors
of the AS5040. Placement tolerances of the die within the
package are ±0.235mm in X and Y direction, using a reference
point of the edge of pin #1 (Figure 43).
ams Datasheet
[v2-12] 2017-Jun-20