AS5050 Datasheet, PDF (17/22 Pages) ams AG – Low Power 10-Bit Magnetic Rotary Encoder

AS5050
Datasheet - Application Information
Daisy Chain, 4 Wire.
Figure 15. Daisy Chain, 4-Wire
MOSI
MISO
UC ^SCK
SS/
MOSI
UC MOSI
Write CMD
SW reset
MISO
SCK
AS5050
I
UC MISO
...
SS /
SS /
1 ^Wire_Mode
Write CMD
SW reset
Write CMD
SW reset
0xFFFF
0xFFFF
0xFFFF
0xFFFF
0xFFFF
0xFFFF
MOSI
UC MOSI Read angle3 Read angle2 Read angle1 Read angle3 Read angle2 Read angle1
MISO _{AS5050 UC MISO}
SCK
SS /
II _SS/
Angle 3
Angle 2
Angle 1
1 ^Wire_Mode
...
Angle 3
...
Angle 2
...
Angle1
MOSI
MISO
AS5050
SCK
III
SS /
1 ^Wire_Mode
8.2 Placement of the Magnet
Non-Linearity Error over Displacement.
As shown in Figure 17, the recommended horizontal position of the magnet axis is over the diagonal center of the IC.
Figure 16 shows a typical error curve at a vertical magnet distance of 1.0mm, measured with a NdFeB N35H magnet with 6mm diameter and
2.5mm height.
The X- and Y- axis of the graph indicate the lateral displacement of the magnet center with respect to the IC center.
At X = Y = 0, the magnet is perfectly centered over the IC. The total displacement plotted on the graph is for ±1mm in both directions.
The Z-axis displays the worst case INL error over a full turn at each given X-and Y- displacement. The error includes the quantization error of ±½
LSB. At the sample shown in Figure 16, the accuracy for a centered magnet is better than 0.5°. Within a radius of 0.5mm, the accuracy is about
1.0° (spec = 1.41° over temperature).
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Revision 1.12
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