HAL 710, HAL 730
DATA SHEET
5.5. 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. 5–1). 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.
R
V
220 Ω
R
R
L
2.4 kΩ
2.4 kΩ
V
1
L
DD
3 S1-Output
2 S2-Output
V
V
EMC
P
4.7 nF
20 pF
20 pF
4
GND
Fig. 5–1: Test circuit for EMC investigations
5.6. Start-up Behavior
Due to the active offset compensation, the sensors
have an initialization time (enable time ten(O)) after
applying the supply voltage. The parameter ten(O) is
specified in the “Characteristics” (see Section 3.6. on
page 11).
During the initialization time, the output states are not
defined and the outputs can toggle. After ten(O), both
outputs will be either high or low for a stable magnetic
field (no toggling) and the Count Output will be low if
the applied magnetic field B exceeds BON. The Count
Output will be high if B drops below BOFF. The Direc-
tion Output will have the correct state after the second
edge (rising or falling) in the same direction.
The device contains a Power-On Reset circuit (POR)
generating a reset when VDD rises. This signal is used
to disable Test Mode. The generation of this reset sig-
nal is guaranteed when VDD at the chip rises to a mini-
mum 3.8 V in less than 4 µs monotonically. If this con-
dition is violated, the internal reset signal might be
missing. Under these circumstances, the chip will still
operate according to the specification, but the risk of
toggling outputs during ten(O) increases; and for mag-
netic fields between BOFF and BON, the output states
of the Hall sensor after applying VDD will be either low
or high. In order to achieve a well-defined output state,
the applied magnetic field then must exceed BONmax
respectively, drop below BOFFmin
,
.
18
Oct. 13, 2009; DSH000031_002EN
Micronas
MICRONAS [ MICRONAS ]
