HAL805-1 Datasheet, PDF (12/30 Pages) Micronas – Programmable Linear Hall-Effect Sensor

HAL 805
DATA SHEET
Step 1: Input of the registers which need not be
adjusted individually
The register values for the following registers are given
for all applications:
– FILTER
Select the filter frequency: 500 Hz
– RANGE
Select the magnetic field range: 30 mT
– TC
For this magnetic material: 6
– TCSQ
For this magnetic material: 14
– CLAMP-LOW
For our example: 0.5 V
– CLAMP-HIGH
For our example: 4.5 V
Enter these values in the software, and use the “write
and store” command for permanently writing the val-
ues in the registers.
Step 2: Calculation of V_OQ and Sensitivity
There are two ways to calculate the values for V_OQ
and Sensitivity.
Manual Calculation:
Set the system to calibration point 1 (angle 1 = −25°)
and read the register ADC-READOUT. For our exam-
ple, the result is ADC-READOUT1 = −2500.
Next, set the system to calibration point 2 (angle 2 =
25°), and read the register ADC-READOUT again. For
our example, the result is ADC-READOUT2 = +2350.
With these measurements and the targets V_OUT1 =
4.5 V and V_OUT2 = 0.5 V, the values for Sensitivity and
V_OQ are calculated as
Sensitivity =
4.5 V − 0.5 V
−2500 − 2350
2048
* _{5 V} = −0.3378
V_OQ = 4.5 V −
−2500 * (−0.3378) * 5 V _{= 2.438 V}
2048
Software Calibration:
Use the menu CALIBRATE from the PC software and
enter the values 4.5 V for V_OUT1 and 0.5 V for V_OUT2.
Set the system to calibration point 1 (angle 1 = −25°),
hit the button “Read ADC-Readout1”, set the system to
calibration point 2 (angle 2 = 25°), hit the button “Read
ADC-Readout2”, and hit the button “Calculate”. The
software will then calculate the appropriate V_OQ and
Sensitivity.
This calculation has to be done individually for each
sensor. Now, write the calculated values with the “write
and store” command into the HAL805 for program-
ming the sensor.
Step 3: 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.
Warning: This register cannot be reset!
12
Feb. 14, 2006; 6251-513-3DS
Micronas