1.1. Features:
– switching offset compensation at typically 62 kHz
– operates from 3.8 V to 24 V supply voltage
– overvoltage protection at all pins
– reverse-voltage protection at VDD-pin
– magnetic characteristics are robust regarding
mechanical stress effects
– short-circuit protected open-drain output by thermal
shut down
– operates with static magnetic fields and dynamic
magnetic fields up to 10 kHz
– constant switching points over a wide supply voltage
range
– the decrease of magnetic flux density caused by rising
temperature in the sensor system is compensated
by a built-in negative temperature coefficient
of the magnetic characteristics
– ideal sensor for applications in extreme automotive
and industrial environments
– EMC corresponding to ISO 7637

2. Functional Description
The HAL 5xx sensors are monolithic integrated circuits
which switch 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 decreasing induction
of magnets at higher temperatures. If the magnetic
field exceeds the threshold levels, the open drain output
switches to the appropriate state. The built-in hysteresis
eliminates oscillation and provides switching
behavior of output without bouncing.
Magnetic offset caused by mechanical stress is compensated
for by using the “switching offset compensation
technique”. Thus, an internal oscillator provides a
two-phase clock. The Hall voltage is sampled at the
end of the first phase. At the end of the second phase,
both sampled and actual Hall voltages are averaged
and compared with the actual switching point. Subsequently,
the open drain output switches to the appropriate
state. The time from crossing the magnetic switching
level to switching of output can vary between zero
and 1/fosc.
Shunt protection devices clamp voltage peaks at the
output pin and VDD pin together with external series
resistors. Reverse current is limited at the VDD pin by
an internal series resistor up to −15 V. No external
reverse protection diode is needed at the VDD pin for
reverse voltages ranging from 0 V to −15 V.