What this hall latch does on your board
The TLI49611MXTSA1 is a south-pole-activated latch from Infineon's automotive-qualified Hall switch family. It switches the open-drain output low when the magnetic field exceeds 3.5 mT (typical) and releases at -3.5 mT, giving you a clean digital signal for position or speed sensing in a brushed-DC motor, transmission, or valve actuator. Rated across a -40°C to 125°C junction temperature range, it keeps the trip points stable when mounted near an engine block or exhaust manifold where the ambient air hits 105°C and the self-heating of the sensor adds another 10–15°C.
Magnetic thresholds and what they mean for your air gap
The 3.5 mT operate point is a typical value at 25°C — the actual threshold shifts with temperature, but the temperature-compensated design keeps the drift within the datasheet corridor so you don't lose the latch at cold crank or hot soak. The -3.5 mT release gives you 7 mT of hysteresis, which prevents output chatter when the target magnet sits at a constant distance and the field fluctuates from vibration. With a 2.5 mA supply current and 25 mA maximum output sink, the part runs directly off a 3 V rail without a separate regulator. The open-drain output lets you wire-OR multiple sensors on a shared pull-up to a 5 V or 3.3 V microcontroller input.
Sourcing and lifecycle status
The SOT23-3 package is widely second-sourced, and the part is available in Tape & Reel or Cut Tape for prototype or low-volume builds. For a BOM line that needs a guaranteed supply path, we source this against your RFQ quantity. Confirm the target magnet polarity (south pole) and the 3 V supply before committing the layout — the footprint is standard SOT23-3, but the magnetic response is unipolar, not omnipolar.