am8192b RLS, am8192b Datasheet - Page 12

• Manufacturer Part Number: am8192b
• Description: Angular Magnetic Encoder Ic
• Manufacturer: RLS

Data sheet
AM8192BD01_05
Issue 5, 14
Nonlinearity
Nonlinearity is defined as the difference between the actual angular position of the magnet and the angular
position output from the AM8192B. There are different types of nonlinearity.
Differential nonlinearity is the difference between the measured position step and the ideal position step.
The position step is the output position difference between any two neighboring output positions, while the
ideal position step is 360° divided by the resolution. Differential nonlinearity is mainly caused by noise. An
additional 0.02° of differential nonlinearity is caused by the interpolator. Differential nonlinearity is always less
than one position step because there is a system that prevents missing codes. Fig. 15 shows a typical
differential nonlinearity plot of the AM8192B with 12 bit resolution, 22 nF filtering and default parameters.
Integral nonlinearity is the total position error of the AM8192B output. Integral nonlinearity includes all
position errors but does not include the quantization error. Integral nonlinearity is minimized during production
to better than ±0.2°. Fig. 16 shows a typical integral nonlinearity plot of the AM8192B with 12 bit resolution, a
perfectly aligned magnet, 22 nF filtering and default parameters. Integral nonlinearity can increase if the
default parameters are changed. The effects of different parameters to integral nonlinearity are described
separately.
© 2009 RLS d.o.o.
Fig. 17: Typical integral nonlinearity when the chip is
-0.02
-0.04
-0.06
-0.08
0.08
0.06
0.04
0.02
-0.1
0.1
-0.1
-0.2
-0.3
-0.4
-0.5
0.5
0.4
0.3
0.2
0.1
0
0
0
0
Fig. 15: Typical differential nonlinearity
th
45
45
January 2009
displaced for 0.2 mm
90
90
135
Angle position
135
Angle position
180
180
225
225
270
270
315
315
360
360
A
-0.05
-0.15
0.15
0.05
-0.1
0.1
0
0
Fig. 16: Typical integral nonlinearity
45
90
associate company
135
Angle position
180
225
270
315
360
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