HAL320
Differential Hall Effect Sensor IC
in CMOS technology
Release Notes: Revision bars indicate significant
changes to the previous edition.
1. Introduction
The HAL 320 is a differential Hall switch produced in
CMOS technology. The sensor includes 2 temperature-
compensated Hall plates (2.25 mm apart) with active off-
set compensation, a differential amplifier with a Schmitt
trigger, and an open-drain output transistor (see Fig.
2–1).
The HAL 320 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
ΔB
= B
S1
– B
S2
for
correct operation.
Basically, there are two ways to generate the differential
signal
ΔB:
– Rotating a multi-pole-ring in front of the branded side
of the package (see Fig. 3–1, Fig. 3–2, and Fig. 3–3;
Please use HAL 300 only).
– Back-bias applications:
A magnet on the back side of the package generates
a back-bias field at both Hall plates. The differential
signal
ΔB
results from the magnetic modulation of the
back-bias field by a rotating ferromagnetic target
(Please use HAL 320 only).
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 320 is an ideal sensor for target wheel applica-
tions, ignition timing, anti-lock brake systems, and revo-
lution counting in extreme automotive and industrial en-
vironments
The HAL 320 is available in the SMD-package
SOT89B-2 and in the leaded versions TO92UA-3 and
TO92UA-4.
1.1. Features:
DATA SHEET
– distance between Hall plates: 2.25 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 ISO 7637
1.2. Marking Code
All Hall sensors have a marking on the package surface
(branded side). This marking includes the name of the
sensor and the temperature range.
1.3. Operating Junction Temperature Range (T
J
)
The Hall sensors from Micronas are specified to the chip
temperature (junction temperature T
J
).
The HAL 320 is available in the temperature range “A”
only.
A:
T
J
= –40
°C
to +170
°C
The relationship between ambient temperature (T
A
) and
junction temperature (T
J
) is explained in section 4.1. on
page 20.
4
Micronas
MICRONAS [ MICRONAS ]
