SS199EUA datasheet(4/6 Pages) SECELECTRONICS

4 / 6 page

SS199

Unipolar Hall Switch-Low Sensitivity

V3.10

Nov 1, 2013

Application Information

Typical Three-Wire Application Circuit

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 = VCC

2/ R1)

When using a diode, a reverse current cannot flow and the voltage drop is almost constant (≈ 0.7V).

Therefore, a 100 Ω /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 recom-

mended the second figure above 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.

SS199EUA データシート(PDF) 4 Page - SEC Electronics Inc.