Compact 3D magnetometer for consumer applications

Melexis is targeting white goods, consumer electronics, and smart-metering applications with the MLX90392 three-axis magnetic field sensor.

Capable of operating from a 1.8 V power rail shared with other components such as logic devices, it doesn’t require a dedicated LDO or regulator, so simplifying the design, trims bill-of-materials costs and saving PCB space.

It measures just 2 mm x 2.5 mm x 0.4 mm and the sensor features a UTDFN-8 ultra-thin no-lead 8-pin package to help designers tackle space-constrained applications. In addition, a 1.5 µA power-down mode helps save energy and thus maximize runtime in battery-powered applications.

Designed with an integrated thermal sensor, and featuring the I2C communication protocol, the MLX90392 places 16-bit position measurements in X, Y, Z axes, and temperature, onto the I2C bus operating at up to 1 MHz. Two variants are available, allowing a choice of ±50 mT and ±5 mT full-scale range, leveraging Melexis’ Triaxis Hall technology to deliver low noise and best-in-class accuracy.

The ±50 mT 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 traditional position sensing with potentiometers.

For position sensing which requires a small magnetic range, and for precise position measurement where noise is a critical design parameter, the ±5 mT variant has sensitivity of 0.15 µT/LSB and typical RMS noise down to 0.3 µT.

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