HAL856 Datasheet, PDF (15/42 Pages) Micronas – Programmable Linear Hall-Effect Sensor with Arbitrary Output Characteristic (2-Wire)

DATA SHEET
HAL 856
2.3.2. Example: Calibration of an Angle Sensor
The following description explains the calibration pro-
cedure using an angle sensor with a HAL856 as an
example. The required output characteristic is shown
in Fig. 2–6.
– the angle range is from −25° to 25°
– temperature coefficient of the magnet: −500 ppm/K
%
100
Output ₉₀
Duty
Cycle ₈₀
70
60
50
40
30
20
First Calibration Point
10
HAL 856
Second Calibration Point
Linear
Sine
-30 -20 -10 0 10 20 30 ^°
Angle
Linear
Fig. 2–_S6_in:_e Examp0le for output characteristics
Step 1: Input of the registers which need not be
adjusted individually
The register values for the following registers are given
for all applications:
– FILTER
Select the filter frequency: 500 Hz
– RANGE
Select the magnetic field range: 40 mT
– TC
For this magnetic material: 6
– TCSQ
For this magnetic material: 14
– OUTPUT FORMAT
Select the output format: PWM
– OUTPUT PERIOD
Select the output format: 8 ms
– PARTNUMBER
For this example: 1
– LOW CURRENT
For this example: 6 mA
– HIGH CURRENT
For this example: 14 mA
– OFFSET CORRECTION
For this example: none
– SLEW RATE
For this example: 0 (fastest)
Enter these values in the software, and use the “write
and store” command for permanently writing the val-
ues in the registers.
Step 2: Initialize DSP
– SHIFT
Select Shift: 50%
– SLOPE
Select Slope: 0.1938 (see Table 2–9 on page 14)
– OUTPUT CHARACTERISTIC
Select output characteristic: ’Linear Standard’
Step 3: Define Calibration Points
The Micronas software PC856 uses default settings
DOUT1_NOM = 0 and DOUT2_NOM = 3968.
DOUT1_NOM corresponds to the angle position −25°,
DOUT2_NOM to +25°.
Micronas
March 23, 2010; DSH000142_002EN
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