Unipolar Hall switch with a 2.5 V rail and 22.7 mT operate point
The DRV5021A3QDBZR is a unipolar Hall-effect switch from Texas Instruments, part of the DRV5021 family. It switches on in the presence of a south pole magnetic field above 22.7 mT and releases when the field drops below 6.7 mT. The SOT-23-3 surface-mount package keeps the footprint small for PCB integration.
What the magnetic thresholds mean for your application
The 22.7 mT operate point and 6.7 mT release point define a 16 mT hysteresis band. This means the switch turns on at a relatively strong field and stays on until the field drops well below the operate level, giving clean switching without chatter near the threshold. An un-compensated Hall sensor would drift several mT over that span; this part holds the switch points tight enough for position sensing in an engine bay or industrial enclosure.