AS5043
Data Sheet – Angular Output Tolerances
18 Angular Output Tolerances
18.1 Accuracy; Digital Outputs
Accuracy is defined as the error between measured angle and actual angle. It is influenced by several factors:
the non-linearity of the analog-digital converters,
internal gain and mismatch errors,
non-linearity due to misalignment of the magnet
As a sum of all these errors, the accuracy with centered magnet = (Errmax – Errmin)/2 is specified as better than ±0.5
degrees @ 25°C (see Figure 23).
Misalignment of the magnet further reduces the accuracy. Figure 22 shows an example of a 3D-graph displaying non-
linearity over XY-misalignment. The center of the square XY-area corresponds to a centered magnet (see dot in the
center of the graph). The X- and Y- axis extends to a misalignment of ±1mm in both directions. The total misalignment
area of the graph covers a square of 2x2 mm (79x79mil) with a step size of 100µm.
For each misalignment step, the measurement as shown in Figure 23 is repeated and the accuracy
(Errmax – Errmin)/2 (e.g. 0.25° in Figure 23) is entered as the Z-axis in the 3D-graph.
18.2 Accuracy; Analog Output
The analog output has the same accuracy as the digital output with the addition of the nonlinearities of the DAC and the
OPAMP (+/-1LSB; see Table 5 and 0).
Figure 22: Example of Linearity Error over XY Misalignment
Linearity Error over XY-misalignment [°]
6
5
4
°
3
800
500
200
-100
-400
-700
-1000
2
1
x
0
y
The maximum non-linearity error on this example is better than ±1 degree (inner circle) over a misalignment radius of
~0.7mm. For volume production, the placement tolerance of the IC within the package (±0.235mm) must also be taken
into account.
The total nonlinearity error over process tolerances, temperature and a misalignment circle radius of 0.25mm is specified
better than ±1.4 degrees.
The magnet used for this measurement was a cylindrical NdFeB (Bomatec® BMN-35H) magnet with 6mm diameter and
2.5mm in height.
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