as5311 austriamicrosystems, as5311 Datasheet - Page 17

• Manufacturer Part Number: as5311
• Description: High Resolution Magnetic Linear Encoder
• Manufacturer: austriamicrosystems

AS5311
Data Sheet
10 Measurement Data Example
Figure 15 shows typical test results of the accuracy obtained by a commercially available multi-pole magnetic
strip.
The graph shows the accuracy over a stroke of 8mm at two different vertical gaps, 0.2mm and 0.4mm. As
displayed, the accuracy is virtually identical (about +/- 10µm) for both airgaps due to the automatic gain control
of the AS5311 which compensates for airgap changes.
The accuracy depends greatly on the length and strength of each pole and hence from the precision of the tool
used for magnetization as well as the homogeneity of the magnet material. As the error curve in the example
below does not show a repetitive pattern for each pole pair (each 2.0mm), this is most likely an indication that
the pole lengths of this particular sample do not exactly match. While the first pole pair (0...2mm) shows the
greatest nonlinearities, the second pole (2…4mm) is very precise, etc…
Figure 15: Sample test results of INL at different airgaps
Note: the magnet sample used in Figure 15 is a 10-pole plastic bonded ferrite magnet as shown in Figure 13.
The corresponding magnet datasheet (MS10-10) is available for download from the austriamicrosystems
website, magnet samples can be ordered from the austriamicrosystems online web shop.
www.austriamicrosystems.com
-10
-15
-20
-25
25
20
15
10
-5
5
0
0
1000
2000
3000
INL MS10-10
Revision 1.00
X [µm]
4000
5000
6000
7000
z= 200µ
z= 400µ
8000
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