HAL54X Datasheet, PDF (27/28 Pages) Micronas – Hall-Effect Sensor Family

DATA SHEET
HAL 54x
5. Application Notes
5.1. 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
temperature T_A).
T_J = T_A + ΔT
At static conditions and continuous operation, the fol-
lowing 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 appli-
cation.
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
5.2. Extended Operating Conditions
All sensors fulfill the electrical and magnetic character-
istics when operated within the Recommended Oper-
ating Conditions (see page 13).
Supply Voltage Below 4.3 V
The devices contain a Power-on Reset (POR) and an
undervoltage reset. For V_DD < V_reset the output state is
high. For V_reset < V_DD < 4.3 V the device responds to
the magnetic field according to the specified magnetic
characteristics.
5.3. 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 characteristics table (see page 14).
During the initialization time, the output state for the
HAL54x is “Off-state” (i.e. Output High). After t_en(O),
the output will be high. The output will be switched to
low if the applied magnetic field B is above B_ON.
5.4. EMC and ESD
For applications with disturbances on the supply line or
radiated disturbances, a series resistor and a capacitor
are recommended (see Fig. 5–1). The series resistor
and the capacitor should be placed as closely as pos-
sible to the Hall sensor.
Please contact Micronas for the detailed investigation
reports with the EMC and ESD results.
R_V
220 Ω
V_EMC
V_P
1 V_DD
4.7 nF
2 GND
OUT
3
R_L 1.2 kΩ
20 pF
Fig. 5–1: Test circuit for EMC investigations
Note: The functionality of the sensor below 4.3 V is not
tested. For special test conditions, please con-
tact Micronas.
Micronas
Feb. 12, 2009; DSH000023_003EN
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