HAL320
DATA SHEET
4. Application Notes
4.2. Extended Operating Conditions
Mechanical stress can change the sensitivity of the Hall
plates and an offset of the magnetic switching points
may result. External mechanical stress on the sensor
must be avoided if the sensor is used under back-biased
conditions. This piezo sensitivity of the sensor IC cannot
be completely compensated for by the switching offset
compensation technique.
All sensors fulfill the electrical and magnetic characteris-
tics when operated within the Recommended Operating
Conditions (see page 13).
Supply Voltage Below 4.5 V
Typically, the sensors operate with supply voltages
above 3 V, however, below 4.5 V some characteristics
may be outside the specification.
In order to assure switching the sensor on and off in a
back-biased application, the minimum magnetic modu-
lation of the differential field should amount to more than
10% of the magnetic preinduction.
Note: The functionality of the sensor below 4.5 V is not
tested on a regular base. For special test condi-
tions, please contact Micronas.
If the HAL320 sensor IC is used in back-biased applica-
tions, please contact our Application Department. They
will provide assistance in avoiding applications which
may induce stress to the ICs. This stress may cause
drifts of the magnetic parameters indicated in this data
sheet.
4.3. Start-up Behavior
Due to the active offset compensation, the sensors have
an initialization time (enable time t
the supply voltage. The parameter t
) after applying
en(O)
4.1. Ambient Temperature
is specified in
en(O)
the Electrical Characteristics (see page 13).
Due to the internal power dissipation, the temperature
on the silicon chip (junction temperature T ) is higher
thanthetemperatureoutsidethepackage(ambienttem-
J
During the initialization time, the output state is not de-
fined and the output can toggle. After t , the output
en(O)
perature T ).
A
will be low if the applied magnetic field B is above B
.
ON
The output will be high if B is below B
.
OFF
T = T + ΔT
J
A
For magnetic fields between B
state of the HAL sensor after applying V will be either
low or high. In order to achieve a well-defined output
state, the applied magnetic field must be above B
and B , the output
ON
OFF
Under static conditions and continuous operation, the
following equation applies:
DD
ΔT = I * V * R
DD
DD
th
,
ONmax
respectively, below B
.
OFFmin
For typical values, use the typical parameters. For worst
case calculation, use the max. parameters for I and
DD
R , and the max. value for V from the application.
th
DD
For all sensors, the junction temperature range T is
J
specified. The maximum ambient temperature T
can be calculated as:
Amax
T
Amax
= T
– ΔT
Jmax
20
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