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While ensuring backward compatibility over 2-wires, it introduces fully programmable current levels and magnetic thresholds. This innovation enables the next generation of automotive body electronics, including safety for seat track positioning, smoothness in soft closing doors, and miniaturization of multi-level trunk locks.
Automotive body electronics demand reliable position sensing for safety-critical functions such as seat-track position monitoring, e-frunk latch, HMI control buttons, charging ports, and more. Traditional microswitch-based approaches often require multiple mechanical switches to detect intermediate positions, increasing system complexity, wiring requirements, and potential reliability concerns. At the same time, evolving safety standards and growing vehicle automation are pushing designers toward more integrated and robust sensing solutions, whilst maintaining ECU compatibility.
The MLX92344 incorporates an industry-first dual programmable architecture that allows engineers to assign output current levels directly to the device’s magnetic operating (BOP1, BOP2) and release (BRP1, BRP2) thresholds with temperature compensation for both Neodymium or Ferrite magnets. Designers can configure up to four different current levels, typically 5mA, 10mA, 15mA, and 20mA, within a range of 3 mA to 28 mA, allowing the device to emulate standard microswitch interfaces while maintaining compatibility with existing hardware and ECUs. It can be sensed via standard IO triggers or an ADC, where one needs to adjust software readouts only.
Operating from 2.7 V to 28 V (with 32 V Absolute Maximum Rating for trucks) and supporting the -40°C to +150°C automotive temperature range, the MLX92344 is an ASIL B SEooC, AEC-Q100 qualified and available in TSOT23-3L surface-mount and TO92-3L (UA) through-hole packages. It also offers strong electrostatic discharge (ESD) robustness, supporting 8kV Human Body Model (HBM) and 15kV system-level, ensuring reliable operation in demanding automotive environments.
Device parameters, including switching thresholds, current outputs, diagnostic behavior, and the number of output states, are configured through on-chip non-volatile memory, allowing the MLX92344 to be optimized for different magnet geometries, mechanical tolerances, and system architectures. End-of-line programmability (EoL) allows engineers to trim away any mechanical tolerances in their assembly, thus achieving ultimate accuracy. Variants of the MLX92344 are also available with Integrated Magnetic Concentrator (IMC) technology, enabling detection of lateral magnetic fields and providing greater flexibility in magnet placement and mechanical design.
Addressing New Safety Requirements
One key application is seat-track position sensing, where accurate seat position detection is critical for occupant safety systems.
Newer safety standards require vehicles to detect three seat positions rather than two, ensuring airbags deploy appropriately depending on the driver’s distance from the steering wheel. Instead of adding extra microswitches, the MLX92344 detects all three positions using a single device and a two-wire interface, reducing wiring complexity in seat systems, where harness lengths & size can be significant.
Seat position monitoring is expected to become increasingly important as the automotive industry moves toward higher levels of autonomous driving, where occupants may adopt different seating configurations. And the same needs appear in detecting the extension of the steering column itself with respect to the driver and the seat.
Beyond seat systems, the MLX92344 can simplify electronic latch (e-latch) mechanisms for doors, hoods, and trunks by replacing multiple microswitches with a single contactless device. Detecting four mechanical states is particularly valuable in soft-close mechanisms, where doors or trunks are automatically pulled closed after reaching an intermediate semi-latch position. Moreover, one can detect fully open, semi-latched, fully-latched and over-pushed, mapping the whole end-start motion.
The device can also support electric vehicle charge port monitoring, detecting the position of the charge port door or connector mechanism. Not only does it bring safety to high voltage charging but it also adds comfort functions like push-to-open and more. Other applications include automatic gear shifters, park locks, disconnect units, and seatbelt buckles.
“With this programmable architecture, we give automotive engineers a smarter way to replace multiple microswitches while improving on safety requirements,” said Minko Daskalov, Product Line Director at Melexis. “By combining configurable current outputs linked to magnetic switching thresholds, the MLX92344 enables engineers to design smaller, safer, and more flexible body electronics systems.”
About Melexis
Melexis (melexis.com) engineers microelectronic solutions. These solutions facilitate the work of our customers. By easy integration. By taking innovation one step further. By providing a competitive advantage. Our technology makes cars and other products smarter, safer and greener. Our sensors capture data from the analog world and comprehend these data digitally. Our drivers make sure customers can bring their products to life. As we always have a plan, we come with the right products at the right moment so our customers stay one step ahead of the competition. That’s what we call inspired engineering.
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