HAL856 Datasheet, PDF (11/42 Pages) Micronas – Programmable Linear Hall-Effect Sensor with Arbitrary Output Characteristic (2-Wire)

DATA SHEET
HAL 856
Output Period
The OUTPUT PERIOD register defines the PWM
period of the output signal.
Table 2–4: OUTPUT PERIOD register definition
PWM Output Period
128 ms; 12-bit resolution
64 ms; 12-bit resolution
32 ms; 12-bit resolution
16 ms; 12-bit resolution
8 ms; 12-bit resolution
4 ms; 11-bit resolution
2 ms; 10-bit resolution
1 ms; 9-bit resolution
Bit Setting
0
1
2
3
4
5
6
7
Output Bittime
The OUTPUT BITTIME register defines the bit time of
the Biphase-M output signal. OUTPUT BITTIME is
“sub”-register of the SPECIAL CUSTOMER register.
Table 2–5: OUTPUT BITTIME register definition
Biphase-M Output Bit Time Bit Setting
40 μs
0
84 µs
1
168 µs
2
320 µs
3
700 µs
11
1.6 ms
4
3.2 ms
5
6.4 ms
7
Note: Setting the Biphase-M bit time to 40 μs simulta-
neously switches the programming telegram to
the same bit time. Hence after writing the
OUTPUT BITTIME register the timing of the pro-
gramming device has to be set accordingly.
TC and TCSQ
The temperature dependence of the magnetic sensitiv-
ity can be adapted to different magnetic materials in
order to compensate for the change of the magnetic
strength with temperature. The adaption is done by
programming the TC (Linear Temperature Coefficient)
and the TCSQ registers (Quadratic Temperature Coef-
ficient). Thereby, the slope and the curvature of the
temperature dependence of the magnetic sensitivity
can be matched to the magnet and the sensor assem-
bly. As a result, the output signal characteristic can be
fixed over the full temperature range. The sensor can
compensate for linear temperature coefficients ranging
from about −2100 ppm/K up to 600 ppm/K and qua-
dratic coefficients from about −5 ppm/K² to 5 ppm/K².
Please refer to Section 4.3. on page 30 for the recom-
mended settings for different linear temperature coeffi-
cients.
Slope
The SLOPE register contains the parameter for the
multiplier in the DSP. The Slope is programmable
between −4 and 4. The register can be changed in
steps of 0.00049. Slope = 1 corresponds to an
increase of the output signal by 100% if the digital
value at the A/D-converter output increases by 2048.
For all calculations, the digital value after the digital
signal processing is used. This digital information is
readable from the DIGITAL OUTPUT register.
Shift
The SHIFT register contains the parameter for the
adder in the DSP. Shift is the output signal without
external magnetic field (B = 0 mT) and programmable
from −100% up to 100%. For calibration in the system
environment, a 2-point adjustment procedure is rec-
ommended. The suitable Slope and Shift values for
each sensor can be calculated individually by this pro-
cedure.
Part Number
In case of Biphase-M output, a part number can be
defined. This part number will be sent during power-on
of the sensor if the PARTNUMBER ENABLE bit is set.
Afterwards, the sensor will send the digital value corre-
sponding to the applied magnetic field.
– The PARTNUMBER ENABLE bit is part of the
SPECIAL CUSTOMER register.
– The OUTPUT PERIOD register defines the time
interval for which the part number is sent.
Micronas
March 23, 2010; DSH000142_002EN
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