HAL300_1 Datasheet, PDF (20/22 Pages) Micronas – Differential Hall Effect Sensor IC

HAL300
DATA SHEET
4. Application Notes
Mechanical stress can change the sensitivity of the Hall
plates and an offset of the magnetic switching points
may result. External mechanical stress to the package
can influence the magnetic parameters if the sensor is
used under back-biased applications. This piezo sensi-
tivity of the sensor IC cannot be completely compen-
sated for by the switching offset compensation tech-
nique.
For back-biased applications, the HAL 320 is recom-
mended. In such cases, 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 indi-
cated in this data sheet.
4.1. Ambient Temperature
Due to the internal power dissipation, the temperature
on the silicon chip (junction temperature T_J) is higher
than the temperature outside the package (ambient tem-
perature T_A).
T_J = T_A + ΔT
Under static conditions and continuous operation, the
following equation applies:
ΔT = I_DD * V_DD * R_th
For typical values, use the typical parameters. For worst
case calculation, use the max. parameters for I_DD and
R_th, and the max. value for V_DD from the application.
For all sensors, the junction temperature range T_J is
specified. The maximum ambient temperature T_Amax
can be calculated as:
T_Amax = T_Jmax – ΔT
4.2. Extended Operating Conditions
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.
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.
4.3. Start-up Behavior
Due to the active offset compensation, the sensors have
an initialization time (enable time t_en(O)) after applying
the supply voltage. The parameter t_en(O) is specified in
the Electrical Characteristics (see page 14).
During the initialization time, the output state is not de-
fined and the output can toggle. After t_en(O), the output
will be low if the applied magnetic field B is above B_ON.
The output will be high if B is below B_OFF.
For magnetic fields between B_OFF and B_ON, the output
state of the HAL sensor after applying V_DD will be either
low or high. In order to achieve a well-defined output
state, the applied magnetic field must be above B_ONmax,
respectively, below B_OFFmin.
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