TLE5009

Specification

Data Sheet

21

Rev. 1.1, 2012-04

Figure 11

Orthogonality error

There is another more accurate way to determine the orthogonality error. The orthogonality can be calculated out

of the magnitude of two 90° angle shifted components. Possible angle combinations are 45° and 135°, 135° and

225°, 225° and 315° or 315° and 45°.

The angle value is given by the angle sensor. No reference is necessary. Therefore the final parameters of

amplitude and offset (Chapter 3.4.4.2) should be used.

At an angle output of 45° the corresponding Y(sin) and X(cos) values can be read out. This has been done also

at 135° (Figure 12).

Next step is to calculate the length of the magnitudes (Equation (14)):

(14)

With these magnitudes the orthogonality can be calculated (Equation (15)):

(15)

2

135

2

135

135

2

45

2

45

45

Y

X

M

Y

X

M

+

=

+

=

)

arctan(

*

2

45

135

45

135

M

M

M

M

+

−

=

ϕ