Compact and low-voltage 3D magnetometer for consumer applications

Melexis targets white goods, consumer electronics, and smart-metering applications with the MLX90392 three-axis magnetic field sensor, which can run from a 1.8V power rail shared with other components such as logic devices.

Needing no dedicated LDO or regulator, the competitively priced device simplifies design, cuts BOM costs and saves PCB space. Measuring only 2mm x 2.5mm x 0.4mm, the sensor features a UTDFN-8 ultra-thin no-lead eight-pin package to assist designers in tackling space-constrained applications. Also, a 1.5µA power-down mode helps save energy and therefore maximise runtime in battery-powered applications.

With an integrated thermal sensor and featuring an I2C communication protocol, the sensor places 16-bit position measurements in X, Y, Z axes and temperature onto the I2C bus operating at up to 1MHz. Two versions are available, providing a choice of ±50mT and ±5mT full-scale range, leveraging the company’s patented Triaxis Hall technology to achieve low noise and best-in-class accuracy.

The ±50mT range is optimal for position measurement in HMI applications, door-closure detection in white goods and access-control systems, anti-tamper for smart meters, and contactless joysticks that save the power dissipated by the conventional position sensing with potentiometers. For position sensing, which requires a small magnetic range, and for precise position measurement where noise is a crucial design parameter, the ±5mT variant has sensitivity of 0.15µT/LSB and typical RMS noise down to 0.3µT.

Both devices support single-measurement and continuous-measurement modes, giving outstanding design flexibility, while self-test status, data-ready, and magnetic sensor-overflow indication provide comprehensive diagnostics.