SS109
Unipolar Hall Switch
Application Information
It is strongly recommended that an external bypass capacitor be connected (in close proximity to the Hall sensor)
between the supply (VDD Pin) and ground (GND Pin) of the device to reduce both external noise and noise generated
by the chopper stabilization technique. As is shown in the following two figures, a 0.1μF capacitor is typical.
For reverse voltage protection, it is recommended to connect a resistor or a diode in series with the VDD pin. When
using a resistor, three points are important:
- the resistor has to limit the reverse current to 50mA maximum (VCC / R1 ≤ 50mA)
- the resulting device supply voltage VDD has to be higher than VDD min (VDD = VCC – R1*IDD
)
- the resistor has to withstand the power dissipated in reverse voltage condition (PD = VCC2/R1)
When using a diode, a reverse current cannot flow and the voltage drop is almost constant (≈0.7V).
Therefore, a 100Ω/0.25W resistor for 5V application and a diode for higher supply voltage are recommended. Both
solutions provide the required reverse voltage protection.
When a weak power supply is used or when the device is intended to be used in noisy environment, it is
recommended that the second figure is used.
The low-pass filter formed by R1 and C1 and the Zener diode Z1 bypass the disturbances or voltage spikes occurring
on the device supply voltage VDD. The diode D1 provides additional reverse voltage protection.
Automotive and Severe Environment
Typical Three-Wire Application Circuit
Protection Circuit
R1:100
VDD
VDD
R2
C2
C1
R2
C2
C1
D1
Z1
OUT
OUT
SS109
SS109
GND
GND
ESD Precautions
Electronic semiconductor products are sensitive to Electro Static Discharge (ESD).
Always observe Electro Static Discharge control procedures whenever handling semiconductor products.
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V3.10 Nov 1, 2013