SS5781
Unipolar Hall Switch-Low Sensitivity
Automotive and Harsh, Noisy Environments Three-Wire Circuit
Application Comments
For proper operation, a 100nF bypass capacitor should be placed as close as possible to the device between the VDD and ground pin.
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)
Using a diode, a reverse current cannot flow and the voltage drop is almost constant (0.7V).
Therefore, a 100ꢀ/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 figure 13.3
from the Application Information section 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.
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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V2.00 May 1, 2012
SECELECTRONICS [ SEC Electronics Inc. ]
