HAL300
2
Micronas
Differential Hall Effect Sensor IC
in CMOS technology
Introduction
The HAL 300 is a differential Hall switch produced in
CMOS technology. The sensor includes 2 temperature-
compensated Hall plates (2.05 mm apart) with active off-
set compensation, a differential amplifier with a Schmitt
trigger, and an open-drain output transistor (see Fig. 2).
The HAL 300 is a differential sensor which responds to
spatial differences of the magnetic field. The Hall volt-
ages at the two Hall plates, S
1
and S
2
, are amplified with
a differential amplifier. The differential signal is
compared with the actual switching level of the internal
Schmitt trigger. Accordingly, the output transistor is
switched on or off.
The sensor has a bipolar switching behavior and re-
quires positive and negative values of
B = B
S1
B
S2
for
correct operation.
The HAL 300 is an ideal sensor for applications with a ro-
tating multi-pole-ring in front of the branded side of the
package (see Fig. 4 and Fig. 5), such as ignition timing,
anti-lock brake systems, and revolution counting.
For applications in which a magnet is mounted on the
back side of the package (back-biased applications), the
HAL 320 is recommended.
The active offset compensation leads to constant mag-
netic characteristics over supply voltage and tempera-
ture.
The sensor is designed for industrial and automotive ap-
plications and operates with supply voltages from 4.5 V
to 24 V in the ambient temperature range from 40
C
up to 150
C.
The HAL 300 is available in a SMD-package (SOT-89A)
and in a leaded version (TO-92UA).
Features:
distance between Hall plates: 2.05 mm
operates from 4.5 V to 24 V supply voltage
switching offset compensation at 62 kHz
overvoltage protection
reverse-voltage protection at V
DD
-pin
short-circuit protected open-drain output by thermal
shutdown
operates with magnetic fields from DC to 10 kHz
output turns low with magnetic south pole on branded
side of package and with a higher magnetic flux densi-
ty in sensitive area S1 as in S2
on-chip temperature compensation circuitry mini-
mizes shifts of the magnetic parameters over temper-
ature and 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 hystere-
sis
EMC corresponding to DIN 40839
Marking Code
Type
Temperature Range
A
E
C
HAL 300SO,
HAL 300UA
300A
300E
300C
Operating Junction Temperature Range (T
J
)
A: T
J
= 40
C to +170
C
E: T
J
= 40
C to +100
C
C: T
J
= 0
C to +100
C
The relationship between ambient temperature (T
A
) and
junction temperature (T
J
) is explained on page 11.
Hall Sensor Package Codes
Type: 300
HAL XXXPA-T
Temperature Range: A, E, or C
Package: SO for SOT-89A,
UA for TO-92UA
Type: 300
Package: TO-92UA
Temperature Range: T
J
= 40
C to +100
C
Example: HAL 300UA-E
Hall sensors are available in a wide variety of packaging
versions and quantities. For more detailed information,
please refer to the brochure: "Ordering Codes for Hall
Sensors".
HAL300
3
Micronas
Solderability
Package SOT-89A: according to IEC68-2-58
Package TO-92UA: according to IEC68-2-20
OUT
GND
3
2
1
V
DD
Fig. 1: Pin configuration
Functional Description
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.
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
zero and 1/f
osc
.
Shunt protection devices clamp voltage peaks at the
Output-Pin and V
DD
-Pin together with external series
resistors. Reverse current is limited at the V
DD
-Pin by an
internal series resistor up to 15 V. No external reverse
protection diode is needed at the V
DD
-Pin for values
ranging from 0 V to 15 V.
HAL 300
Temperature
Dependent
Bias
Switch
Hysteresis
Control
Comparator
Output
V
DD
1
OUT
3
Clock
GND
2
Fig. 2: HAL 300 block diagram
Short Circuit &
Overvoltage
Protection
Reverse
Voltage &
Overvoltage
Protection
Hall Plate
S1
Hall Plate
S2
t
V
OL
V
OUT
1/f
osc
= 16
s
Fig. 3: Timing diagram
V
OH
D
B
D
B
ON
f
osc
t
t
t
f
t
I
DD
t
HAL300
5
Micronas
Absolute Maximum Ratings
Symbol
Parameter
Pin No.
Min.
Max.
Unit
V
DD
Supply Voltage
1
15
28
1)
V
V
P
Test Voltage for Supply
1
24
2)
V
I
DD
Reverse Supply Current
1
50
1)
mA
I
DDZ
Supply Current through
Protection Device
1
200
3)
200
3)
mA
V
O
Output Voltage
3
0.3
28
1)
V
I
O
Continuous Output On Current
3
30
mA
I
Omax
Peak Output On Current
3
250
3)
mA
I
OZ
Output Current through
Protection Device
3
200
3)
200
3)
mA
T
S
Storage Temperature Range
65
150
C
T
J
Junction Temperature Range
40
40
150
170
4)
C
1)
as long as T
J
max
is not exceeded
2)
with a 220
series resistance at pin 1 corresponding to test circuit 1
3)
t < 2 ms
4)
t < 1000h
Stresses beyond those listed in the "Absolute Maximum Ratings" may cause permanent damage to the device. This
is a stress rating only. Functional operation of the device at these or any other conditions beyond those indicated in the
"Recommended Operating Conditions/Characteristics" of this specification is not implied. Exposure to absolute maxi-
mum ratings conditions for extended periods may affect device reliability.
Recommended Operating Conditions
Symbol
Parameter
Pin No.
Min.
Max.
Unit
V
DD
Supply Voltage
1
4.5
24
V
I
O
Continuous Output On Current
3
20
mA
V
O
Output Voltage
3
24
V
R
v
Series Resistor
1
270
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