What this hall switch does in the assembly
The TLV4961-1TB is a latching bipolar Hall switch from Infineon, meaning it toggles its output state when a south pole of sufficient flux density is applied and latches until a north pole of opposite polarity releases it. The operate point is 3.5 mT; the release point is -3.5 mT. This makes it suitable for brushless-DC motor commutation, position sensing, and speed detection where a rotating magnet passes the sensor. Output is open drain, rated for 25 mA continuous sink current. The 3 V supply rail aligns with low-voltage 3.3 V logic systems commonly used in industrial control boards.
The temperature-compensated feature stabilises the magnetic thresholds across this span, so the operate/release window does not drift with the heat from the motor windings.
Package and mounting for the BOM
as a through-hole device. The through-hole footprint is straightforward to hand-assemble or wave-solder; no reflow profile to qualify. The south-pole polarisation means the sensor responds to the south face of the magnet — confirm the magnet orientation in the assembly before committing the BOM position.