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AS5215

Datasheet - Detailed Descr i pti on

For the 6mm magnet (shown in Figure 5), the linear range has a radius of 1.6mm, hence this magnet allows a radial misalignment of 0.5mm

(1.6mm linear range radius; 1mm Hall array radius). Consequently, the larger the linear range, the more radial misalignment can be tolerated. By

contrast, the slope of the linear range decreases with increasing magnet diameter, as the poles are further apart. A smaller slope results in a

smaller differential signal, which means that the magnet must be moved closer to the IC (smaller airgap) or the amplification gain must be

increased, which leads to a poorer signal-to-noise ratio. More noise results in more jitter at the angle output. A good compromise is a magnet

diameter in the range of 5…8mm.

Figure 5. Vertical Magnetic Field Across the Center of a Cylindrical Magnet

Small Diameter Magnet (<6mm)

Large Diameter Magnet (>6mm)

+ stronger differential signal =

good signal / noise ratio,

larger airgaps

+ wider linear range =

larger horizontal misalignment area

- shorter linear range =

smaller horizontal misalignment area

- weaker differential signal =

poorer signal / noise ratio,

smaller airgaps

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

X -displacement [mm]

Hall elements (side view)