SS139
Unipolar Hall Switch-Low Sensitivity
Application Comments
For proper operation, a 100nF bypass capacitor should be placed as close as possible to the device between the V
DD
and ground pin.
For reverse voltage protection, it is recommended to connect a resistor or a diode in series with the V
DD
pin.
When using a resistor, three points are important:
- the resistor has to limit the reverse current to 50mA maximum (V
CC
/ R1
50mA)
- the resulting device supply voltage V
DD
has to be higher than V
DD
min (V
DD
= V
CC
– R1.I
DD
)
- the resistor has to withstand the power dissipated in reverse voltage condition (P
D
= V
CC 2
/ R1)
When using a diode, a reverse current cannot flow and the voltage drop is almost constant (
0.7V).
Therefore, a 100
/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 V
DD
. 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.
Package Information
Package LH, 3-Pin SOT-23:
4
V2.10
May 1, 2012
SECELECTRONICS [ SEC Electronics Inc. ]
