AS5311

Data Sheet

www.austriamicrosystems.com

Revision 1.01

19 - 23

11 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

INL MS10-10

-25

-20

-15

-10

-5

0

5

10

15

20

25

0

1000

2000

3000

4000

5000

6000

7000

8000

X [µm]

z= 200µ

z= 400µ

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.