HAL710_2 Datasheet, PDF (2/2 Pages) Micronas – Hall-Effect Sensors with Direction Detection

PRODUCT INFORMATION
HAL 710/730
Available Types and Switching Behavior
Type
HAL 710
HAL 730
Direction Output: Definition of Output State
Output high, when edge of comparator 1 precedes
edge of comparator 2
Output high, when edge of comparator 2 precedes
edge of comparator 1
May/2007
System Architecture
The Hall-effect sensor is a monolithic inte-
grated circuit that switches in response to
magnetic fields. If a magnetic field with flux
lines perpendicular to the sensitive area is
applied to the sensor, the biased Hall plate
forces a Hall voltage proportional to this
field. The Hall voltage is compared with the
actual threshold level in the comparator.
The temperature-dependent bias increases
the supply voltage of the Hall plates and
adjusts the switching points to the decreas-
ing induction of magnets at higher tempera-
tures. If the magnetic field exceeds the
threshold levels, the open-drain output
switches to the appropriate state. The built-
in hysteresis eliminates oscillation and pro-
vides switching behavior of output without
bouncing.
Magnetic offset caused by mechanical
stress is compensated for by using the
“switching offset compensation technique”.
Therefore, an internal oscillator provides a
two phase clock. The Hall voltage is sam-
pled at the end of the first phase. At the end
of the second phase, both sampled and
actual Hall voltages are averaged and com-
pared with the actual switching point.
Reverse
1
Voltage and
Overvoltage
V_{DD Protection}
Temperature
Dependent
Bias
Hysteresis
Control
Hall Plate 1
S1
Switch
Clock
4
GND
Hall Plate 2
S2
Switch
Test-Mode
Control
Comparator
Comparator
Direction
Detection
Fig. 1: Block diagram of the HAL 710/730
Short Circuit
and
Overvoltage
Protection
Output
3
Count Output
Output
2
Direction Output
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Edition May 7, 2007; Order No. PI000115-001EN
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