HAL556_1 Datasheet, PDF (24/26 Pages) Micronas – Two-Wire Hall-Effect Sensor Family

HAL55x, HAL56x
DATA SHEET
5. Application Notes
5.1. Application Circuit
Figure 5–1 shows a simple application with a two-wire
sensor. The current consumption can be detected by
measuring the voltage over R_L. For correct functioning
of the sensor, the voltage between pin 1 and 2 (V_DD)
must be a minimum of 4 V. With the maximum current
consumption of 17 mA, the maximum R_L can be calcu-
lated as:
R_Lmax
=
-^V---^S---^U---^P---^m----ⁱ-ⁿ----–----4----V--
17mA
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).
Typically, the sensors operate with supply voltages
above 3 V. However, below 4 V, the current consump-
tion and the magnetic characteristics may be outside
the specification.
Note: The functionality of the sensor below 4 V is not
tested on a regular base. For special test condi-
tions, please contact Micronas.
V_SUP
V_SIG
R_L
2 or x GND
Fig. 5–1: Application circuit 1
For applications with disturbances on the supply line or
radiated disturbances, a series resistor R_V (ranging
from 10 Ω to 30 Ω) and a capacitor both placed close
to the sensor are recommended (see Fig. 5–2). In this
case, the maximum R_L can be calculated as:
R_Lmax
=
-^V---^S---^U---^P---^m----ⁱ-ⁿ----–----4----V--
17mA
–
R_V
V_SUP
V_SIG
R_L
R_V
4.7 nF
1 V_DD
2 or x GND
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 Electrical Characteristics (see
page 14). During the initialization time, the current con-
sumption is not defined and can toggle between low
and high.
HAL 55x:
After t_en(O), the current consumption will be high if the
applied magnetic field B is above B_ON. The current
consumption will be low if B is below B_OFF.
HAL 56x:
In case of sensors with an inverted switching behavior,
the current consumption will be low if B > B_OFF and
high if B < B_ON.
Note: For magnetic fields between B_OFF and B_ON, the
current consumption of the HAL sensor will be
either low or high after applying V_DD. In order to
achieve a defined current consumption, the
applied magnetic field must be above B_ON,
respectively, below B_OFF.
Fig. 5–2: Application circuit 2
24
Aug. 11, 2009; DSH000026_004EN
Micronas