AS5134 PB austriamicrosystems, AS5134 PB Datasheet - Page 29

• Manufacturer Part Number: AS5134 PB
• Description: BOARD PROGRAM AS5134
• Manufacturer: austriamicrosystems

Specifications of AS5134 PB

• Module/board Type: ZIF Socket
• For Use With/related Products: AS5000 Programmer, AS5134
• Lead Free Status / RoHS Status: Lead free by exemption / RoHS compliant by exemption

AS5134
Data Sheet - A p p l i c a t i o n I n f o r m a t i o n
As shown in
Figure 20
(grey zone), the Hall elements are located on the chip at a circle with a radius of 1.1mm. Since the difference between two
opposite Hall sensors is measured, there will be no difference in signal amplitude when the magnet is perfectly centered or if the magnet is
misaligned in any direction as long as all Hall elements stay within the linear range.
For the 6mm magnet (shown in
Figure
20), the linear range has a radius of 1.6mm, hence this magnet allows a radial misalignment of 0.5mm
(1.6mm linear range radius; 1.1mm 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.
Small Diameter Magnet (<6mm)
Large Diameter Magnet (>6mm)
+++ stronger differential signal =
+++ wider linear range =
good signal / noise ratio,
larger horizontal misalignment area
larger airgaps
-- weaker differential signal =
--- shorter linear range =
poorer signal / noise ratio,
smaller horizontal misalignment area
smaller airgaps
Figure 20. Vertical Magnetic Field across the center of a Cylindrical Magnet
Bz; 6mm magnet @ y=0; z=1mm
Hall elements (side view)
X -displacement [mm]
www.austriamicrosystems.com/AS5134
Revision 1.13
29 - 40