Melexis has introduced the MLX90391, a low-power 3D magnetometer for high-volume sensing applications. The new sensor measures magnetic fields across three axes and offers selectable ranges up to ±520 mT, with smart utility meter anti-tampering among its main target applications.
Engineers can select between ±65 mT, ±130 mT, ±260 mT and ±520 mT ranges. This gives the same IC the flexibility to handle position measurement or detect the stronger external magnetic fields that may be used to interfere with utility meter operation.
Selectable Magnetic Sensing up to ±520 mT
The MLX90391 uses Melexis' vertical Hall technology and provides 16-bit digital output for magnetic and temperature data. Its operating modes can be selected at runtime, while individual magnetic axes can be enabled as required. A configurable digital filter is also integrated into the device.
Three wake-up-on-change/interrupt modes can keep the wider system in deep sleep until the MLX90391 detects a defined change in magnetic field. Data-ready output and externally synchronized measurement are available for coordination with an MCU.
Power-down current is 5 nA, with the sensor operating from a 1.7 V to 3.6 V supply. Its ambient operating temperature range extends from -40°C to +125°C.
MLX90391 Targets Smart Meter Anti-Tampering
For designs already using other magnetometers, the MLX90391 comes in a standard TSOT23-6L package with a matching pinout and familiar I²C-compatible digital interface. Melexis says this supports pin-to-pin replacement without requiring significant changes to existing PCB layouts.
While smart utility meter anti-tampering is a key application for the high-field measurement range, the MLX90391 can also be used for contactless position sensing. Melexis lists smart knobs, liquid-level sensing, electronic locks, handheld tool triggers, gaming controls and e-bike gear position sensing among the possible applications.
The MLX90391 sits alongside other devices in Melexis' 3D magnetometer portfolio, including the MLX90394, which targets applications requiring higher accuracy and lower noise.
Samples of the MLX90391 are available now.#
Learn more and read the original announcement at melexis.com.
Technology Overview
The Melexis MLX90391 is a low-power three-axis magnetometer with selectable ±65 mT, ±130 mT, ±260 mT and ±520 mT measurement ranges. It offers 16-bit magnetic and temperature data, a 5 nA power-down mode and an I²C-compatible interface in a TSOT23-6L package.
FAQs
What is the Melexis MLX90391?
The MLX90391 is a low-power 3D magnetometer that measures magnetic fields across three axes, with selectable measurement ranges up to ±520 mT.
How much power does the MLX90391 use?
The MLX90391 has a 5 nA power-down mode and operates from a 1.7 V to 3.6 V supply. Wake-up-on-change modes can keep the wider system asleep until a defined magnetic field change is detected.
Where can the MLX90391 be used?
Applications include smart utility meter anti-tampering, smart knobs, liquid-level sensing, electronic locks, handheld tool triggers, gaming controls and e-bike gear position sensing.
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