AS5040

Data Sheet

www.austriamicrosystems.com

Revision 2.10

24 - 33

The vertical distance should be chosen such that the magnetic field on the die surface is within the specified limits

(see Figure 20). The typical distance “z” between the magnet and the package surface is 0.5mm to 1.8mm with the

recommended magnet (6mm x 2.5mm). Larger gaps are possible, as long as the required magnetic field strength

stays within the defined limits.

A magnetic field outside the specified range may still produce usable results, but the out-of-range condition will be

indicated by MagINCn (pin 1) and MagDECn (pin 2), see Table 3.

Figure 22: Vertical Placement of the Magnet

1.282mm ± 0.15mm

0.576mm ± 0.1mm

z

S

N

Package surface

Die surface

16 Simulation Modelling

Figure 23: Arrangement of Hall Sensor Array on Chip (principle)

With reference to Figure 23, 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.