DATA SHEET
HAL855
2.3. Calibration Procedure
2.3.1. General Procedure
Step 2: Initialize DSP
As the DIGITAL OUTPUT register value depends on
the settings of SLOPE, SHIFT and the OUTPUT
CHARACTERISTIC, these registers have to be initial-
ized with defined values, first:
For calibration in the system environment, the applica-
tion kit from Micronas is recommended. It contains the
hardware for the generation of the serial telegram for
programming (Programmer Board Version 5.1) and the
corresponding software (PC85x) for the input of the
register values.
– ShiftINITIAL = 50%
– OUTPUT CHARACTERISTIC = ’Linear Standard’
(Setpoint 0 = 0, Setpoint 1 = 16, Setpoint 2 = 32, ...,
Setpoint 31 = 496).
For the individual calibration of each sensor in the cus-
tomer application, a two-point adjustment is recom-
mended (see Fig. 2–5 on page 14 for an example).
The calibration shall be done as follows:
– SlopeINITIAL depends on the setting of the digital
low-pass filter (see Table 2–8).
Table 2–8: Initial slope values
Step 1: Input of the registers which need not be
adjusted individually
−3 dB Frequency
SlopeINITIAL
0.2578
80
The magnetic circuit, the magnetic material with its
temperature characteristics, the filter frequency, the
part number and the output format are given for this
application.
160
500
1000
2000
0.2578
0.1938
Therefore, the values of the following registers should
be identical for all sensors of the customer application.
0.1938
0.3398
– FILTER
(according to the maximum signal frequency)
– RANGE
Step 3: Define Calibration Points
(according to the maximum magnetic field at the
sensor position)
For highest accuracy of the sensor, calibration points
near the minimum and maximum input signal are rec-
ommended.
– TC and TCSQ
(depends on the material of the magnet and the
other temperature dependencies of the application)
Define nominal values DOUT1NOM and DOUT2NOM of
the DIGITAL OUTPUT register at the calibration points
1 and 2, respectively.
– OUTPUT FORMAT
(according to the application requirements)
– OUTPUT PERIOD
(according to the application requirements)
Note: Micronas software PC85x uses default settings
– PARTNUMBER
DOUT1NOM = 0 and DOUT2NOM = 3968.
(in case Biphase-M output format is used)
The output is clamped to Setpoint 0 and
Setpoint 31. In the case of “Linear Standard’”,
– OFFSET CORRECTION
– SLEW RATE
Setpoint 0
corresponds
to
DIGITAL
OUTPUT = 0, while Setpoint 31 corresponds to
DIGITAL OUTPUT = 3968.
Write the appropriate settings into the HAL855 regis-
ters.
Micronas
Nov. 26, 2008; DSH000149_003EN
13
MICRONAS [ MICRONAS ]
