DATA SHEET
HAL855
Step 1: Input of the registers which need not be
adjusted individually
Manual Calculation:
1. Set the system to calibration point 1 (angle 1 = 25°)
2. read the register DIGITAL OUTPUT.
The register values for the following registers are given
for all applications:
For our example, the result is
DIGITAL OUTPUT = DOUT1 = 3291.
– FILTER
Select the filter frequency: 500 Hz
– RANGE
3. Set the system to calibration point 2 (angle 2 = −25°)
Select the magnetic field range: 40 mT
4. read the register DIGITAL OUTPUT again.
– TC
For this magnetic material: 6
For our example, the result is
DIGITAL OUTPUT = DOUT2 = 985.
– TCSQ
For this magnetic material: 14
With these measurements and the pre-programming
of the sensor, the values for Slope and Shift are calcu-
lated as:
– OUTPUT FORMAT
Select the output format: PWM
– OUTPUT PERIOD
Select the output format: 8 ms
3968
(985 – 3291)
-------------------------------
Slope =
× 0.1938= –0.3335
– PARTNUMBER
For this example: 1
– OFFSET CORRECTION
For this example: none
100%
-------------
(985 – 2048) × (–0.3335)
--------------------------------------------------------------
= 52.22%
Shift =
× 3968 –
4096
0.1938
– SLEW RATE
For this example: 0 (fastest)
Write the calculated values for Slope and Shift and a
linear output characteristic ranging from 10% to 90%
output duty cycle into the EEPROM memory.
Enter these values in the software, and use the “write
and store” command for permanently writing the val-
ues in the registers.
Software Calibration:
Step 2: Initialize DSP
Use the menu CALIBRATE from the PC software and
enter the values for the registers which are not
adjusted individually. Set the system to calibration
point 1 (angle 1 = 25°), hit the button “Digital Output1”,
set the system to calibration point 2 (angle 2 = −25°),
hit the button “Digital Output2”, and hit the button “Cal-
culate”. The software will then calculate the appropri-
ate Shift and Slope.
– SHIFT
Select Shift: 50%
– SLOPE
Select Slope: 0.1938 (see Table 2–8 on page 13)
– OUTPUT CHARACTERISTIC
Select output characteristic: ’Linear Standard’
This calculation has to be done individually for each
sensor. Now, select an output characteristic from the
selection box “Output Characteristics” and then press
the button “write and store” for programming the sensor.
Step 3: Define Calibration Points
The Micronas software PC85x uses default settings
DOUT1NOM = 0 and DOUT2NOM = 3968.
DOUT1NOM corresponds to the angle position −25°,
DOUT2NOM to +25°.
Step 5: Locking the Sensor
The last step is activating the LOCK function with the
“LOCK” command. Please note that the LOCK function
becomes effective after power-down and power-up of
the Hall IC. The sensor is now locked and does not
respond to any programming or reading commands.
Step 4: Calculation of Shift and Slope
There are two ways to calculate the values for Shift
and Slope.
Warning: This register cannot be reset!
Micronas
Nov. 26, 2008; DSH000149_003EN
15
MICRONAS [ MICRONAS ]
