HAL1000UT-A Datasheet, PDF (10/30 Pages) Micronas – Programmable Hall Switch

HAL 1000
DATA SHEET
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 (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 switching points can be stabilized
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 4.4. on page 23 for the recom-
mended settings for different linear temperature coeffi-
cients.
Sensitivity
The SENSITIVITY register contains the parameter for
the multiplier in the DSP. Sensitivity is programmable
between −4 and 4 in steps of 0.00049. Sensitivity = 1
corresponds to an increase of the signal voltage by
V_DD if the ADC-READOUT increases by 2048.
VOQ
The VOQ register contains the parameter for the
adder in the DSP. V_OQ is the signal voltage without
external magnetic field (B = 0 mT, respectively
ADC-READOUT = 0) and programmable from −V_DD
up to V_DD. For V_DD = 5 V, the register can be
changed in steps of 4.9 mV.
Note: If V_OQ is programmed to a negative voltage, the
maximum signal voltage is limited to:
V_{Signal max} = V_OQ + V_DD
Reference Levels
The LOW-LEVEL and HIGH-LEVEL registers contain
the reference values of the comparator.
The Low-Level is programmable between 0 V and
V_DD/2. The register can be changed in steps of
2.44 mV. The High-Level is programmable between
0 V and V_DD in steps of 2.44 mV.
The four parameters Sensitivity, V_OQ, Low-Level, and
High-Level define the switching points B_ON and B_OFF.
For calibration in the system environment, a 2-point
adjustment procedure is recommended (see
Section 2.3.). The suitable parameter set for each sen-
sor can be calculated individually by this procedure.
LOCKR
By setting this 1-bit register, all registers will be locked,
and the sensor will no longer respond to any supply
voltage modulation. This bit is active after the first
power-off and power-on sequence after setting the
LOCK bit.
Warning: The Lockr register cannot be reset!
ADC-READOUT
This 14-bit register delivers the actual digital value of
the applied magnetic field after filtering but before the
signal processing. This register can be read out and is
the basis for the calibration procedure of the sensor in
the system environment.
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Feb. 3, 2009; DSH000015_003EN
Micronas