HAL700
ADVANCE INFORMATION
10
Micronas
4. Application Notes
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
temperature T
A
).
T
J
= T
A
+
T
At static conditions, the following equation is valid:
T = 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
T
4.2. Extended Operating Conditions
All sensors fulfil the electrical and magnetic character-
istics when operated within the Recommended Oper-
ating Conditions (see page 7)
Supply Voltage Below 3.8 V
Typically, the sensors operate with supply voltages
above 3 V, however, below 3.8 V some characteristics
may be outside the specification.
Note:
The functionality of the sensor below 3.8 V is not
tested. For special test conditions, 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 8)
During initialization time, the output states are not
defined and the outputs can toggle. After t
en(O)
both
outputs will be either high or low for a stable magnetic
field (no toggling). The outputs will be low if the applied
magnetic flux density B exceeds B
ON
and high if B
drops below B
OFF
.
For magnetic fields between B
OFF
and B
ON
, the output
states of the Hall sensor after applying V
DD
will be
either low or high. In order to achieve a well-defined
output state, the applied magnetic flux density must be
above B
ONmax
, respectively, below B
OFFmin
.
4.4. EMC and ESD
For applications that cause disturbances on the supply
line or radiated disturbances, a series resistor and a
capacitor are recommended (see Fig. 4
–
1). The series
resistor and the capacitor should be placed as closely
as possible to the Hall sensor.
Please contact Micronas for detailed investigation
reports with EMC and ESD results.
Fig. 4
–
1:
Test circuit for EMC investigations
1 V
DD
4
GND
3 S1-Output
2 S2-Output
R
V
220
V
EMC
V
P
4.7 nF
R
L
2.4 k
20 pF
R
L
2.4 k
20 pF