HAL300
Solderability
HAL300
Reverse
V
Temperature
Dependent
Bias
Short Circuit &
Overvoltage
Protection
DD
1
– Package SOT-89A: according to IEC68-2-58
– Package TO-92UA: according to IEC68-2-20
Hysteresis
Control
Voltage &
Overvoltage
Protection
Hall Plate
S1
Comparator
V
OUT
Output
3
DD
1
Switch
Hall Plate
S2
OUT
3
Clock
GND
2
2
GND
Fig. 1: Pin configuration
Fig. 2: HAL300 block diagram
Functional Description
f
osc
This Hall effect sensor is a monolithic integrated circuit
with 2 Hall plates 2.05 mm apart that switches in
response to differential magnetic fields. If magnetic
fields with flux lines at right angles to the sensitive areas
are applied to the sensor, the biased Hall plates force
Hall voltages proportional to these fields. The difference
of the Hall voltages is compared with the actual thresh-
old 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 differential
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 the output without oscillation.
t
t
t
t
DB
DB
ON
V
OUT
V
OH
V
OL
I
DD
Magnetic offset caused by mechanical stress at the Hall
plates is compensated for by using the “switching offset
compensation technique”: An internal oscillator pro-
vides a two phase clock (see Fig. 3). The difference of
the Hall voltages is sampled at the end of the first phase.
At the end of the second phase, both sampled differen-
tial Hall voltages are averaged and compared with the
actual switching point. Subsequently, the open drain
output switches to the appropriate state. The amount of
time that elapses from crossing the magnetic switch lev-
el to the actual switching of the output can vary between
t
f
1/f
osc
= 16 µs
Fig. 3: Timing diagram
zero and 1/f
.
osc
Shunt protection devices clamp voltage peaks at the
Output-Pin and V -Pin together with external series
DD
resistors. Reverse current is limited at the V -Pin by an
DD
internal series resistor up to –15 V. No external reverse
protection diode is needed at the V -Pin for values
DD
ranging from 0 V to –15 V.
Micronas
3
MICRONAS [ MICRONAS ]
