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AS5311

Datasheet - A pp l ic a t io n I n f or m a t i on

8.4 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 non-linearities, 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

ams website, magnet samples can be ordered from the ams online web shop.

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