What the ±13 mT trip point means for your design
The TMAG5123D1CQDBZT is an omnipolar Hall-effect switch that triggers its open-drain output when the magnetic flux density exceeds ±13 mT (typical) and releases at ±6.7 mT (typical). The 6.3 mT hysteresis prevents output chatter near the threshold — the switch stays latched until the field drops below the release point, which is the standard behaviour for a switch, not a latch. Because it responds to both north and south poles, the sensor does not care about magnet orientation — a bar magnet passing either pole within range will trigger it. This simplifies mechanical alignment in applications like proximity detection, end-of-travel sensing, or lid-closed detection where the magnet's polarity cannot be guaranteed. The open-drain output requires an external pull-up resistor to the logic supply rail. The switching current is 5.4 mA (max), so the pull-up value should be chosen to keep the output voltage within the logic threshold of the downstream receiver when the output is low.
Temperature range and operating environment
This makes it suitable for under-hood, engine-bay, or industrial enclosures where the ambient temperature cycles between cold start and hot soak. This part operates from a 2.5 V rail, which is common in modern low-power microcontrollers and battery-powered designs. Confirm the supply rail in your system stays within the 2.5 V nominal range; the datasheet's absolute-maximum table (page 4) defines the safe operating area.
The surface-mount package footprint is a standard small-outline transistor (SOT-23) variant; the exact land pattern is in the datasheet's package drawing. No exposed thermal pad — the package dissipates through the leads and the board copper. The part is an omnipolar switch, not a linear sensor — it outputs a digital high/low, not an analog voltage proportional to field strength. The switching threshold is factory-trimmed; no external calibration is needed. The test condition covers the full temperature range, so the trip points are guaranteed across -40°C to 125°C.