DATA SHEET
HAL810
TC and TCSQ
Note:
During application design, it should be taken into
consideration that the maximum and minimum
ADC-READOUT is not exceeded during calibra-
tion and operation of the Hall IC. Consequently,
the maximum and minimum magnetic fields that
may occur in the operational range of a specific
application should not saturate the A/D converter.
Please note that the A/D converter saturates at
magnetic fields well above, respectively below,
the magnetic range limits. This large safety band
between specified magnetic range and true oper-
ational range helps to avoid saturation.
Range
The RANGE bits are the three lowest bits of the
MODE register; they define the magnetic field range
of the A/D converter.
Magnetic Field Range
−30
mT…30 mT
−40
mT…40 mT
−60
mT…60 mT
−75
mT…75 mT
−80
mT…80 mT
−90
mT…90 mT
−100
mT…100 mT
−150
mT…150 mT
Range
0
4
5
1
6
2
7
3
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 adaptation is done by
programming the TC (Temperature Coefficient) and
the TCSQ registers (Quadratic Temperature Coeffi-
cient). 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 characteristic can be fixed
over the full temperature range. The sensor can com-
pensate for linear temperature coefficients ranging
from about
−
3100 ppm/K up to 400 ppm/K and qua-
dratic coefficients from about
−
5 ppm/K² to 5 ppm/K².
Please refer to Section 4.3. on page 23 for the recom-
mended settings for different linear temperature coeffi-
cients.
DCSensitivity
The DCSENSITIVITY register contains the parameter
for the multiplier in the DSP. The DCSensitivity is pro-
grammable between
−
4 and 4. The register can be
changed in steps of 0.00049. DCSensitivity = 1 corre-
sponds to an increase of the output duty cycle by
100% if ADC-READOUT increases by 2048.
For all calculations, the digital value of the A/D con-
verter is used. This digital information is derived
from the magnetic signal and is readable from the
ADC-READOUT register.
DCSensitivity =
ΔDC
OUT
* 2048
ΔADC-Readout
* 100%
DC
OQ
Filter
The FILTER bits are the three highest bits of the
MODE register; they define the
−3
dB frequency of the
digital low pass filter.
−3
dB Frequency
80 Hz
160 Hz
500 Hz
1 kHz
2 kHz
Filter
0
1
DC
OUTmax
= DC
OQ
+100%
The DCOQ register contains the parameter for the
adder in the DSP. DC
OQ
is the output duty cycle with-
out external magnetic field (B = 0 mT, respectively
ADC-READOUT = 0) and programmable from
−100%
to 100%. The register can be changed in steps of
0.0976%.
Note:
If DC
OQ
is programmed as negative values, the
maximum output duty cycle is limited to:
2
3
4
For calibration in the system environment, a 2-point
adjustment procedure (see Section 2.3.) is recom-
mended. The suitable DCSensitivity and DC
OQ
values
for each sensor can be calculated individually by this
procedure.
Micronas
Feb. 6, 2009; DSH000034_003EN
9
MICRONAS [ MICRONAS ]
