Honeywell SS361CT Bipolar Hall Effect Sensor SMT - 5 G to 95 G Range, SOT-23-3 Package

A unipolar sensor responds to a single magnetic pole (typically south), while a bipolar sensor switches based on the polarity, activating with a south pole and deactivating with a north pole. The Honeywell SS361CT's bipolar design makes it ideal for applications requiring detection of alternating magnetic fields, such as in motor commutation or speed sensing with a multi-pole magnet.

An external pull-up resistor is required between the output pin and the supply voltage (Vcc). The value depends on your load current and desired switching speed; a typical value is between 1kΩ and 10kΩ. Ensure the resistor's power rating is sufficient for your chosen supply voltage and that the total current does not exceed the sensor's 20 mA maximum output current.

No, the SS361CT requires a minimum supply voltage of 4V. For 3.3V systems, you must power the sensor from a separate 5V or higher rail. Its open-collector output can safely interface with a 3.3V logic input when pulled up to 3.3V, provided the sensor's Vcc is within its 4-24V operating range.

The operating point (Bop) is the magnetic flux density required to switch the output ON. You must select a magnet and design an air gap so that the field strength at the sensor exceeds the minimum 5 G threshold reliably but stays below the 95 G maximum to avoid potential saturation. Consult magnet datasheets and use magnetic simulation tools or physical testing to validate the field strength at your intended sensing distance.