Melexis introduces automotive-grade 3D Hall effect sensor

Melexis has announced the MLX90395 Triaxis Magnetometer Node, an automotive-grade (AEC-Q100) monolithic sensor that uses the Hall effect to provide contactless sensing in three dimensions.

The functionality of the MLX90395 is defined through the system processor, rather than hardwired into the device itself.

The MLX90395 offers both I2C and SPI interfaces, making it simple to integrate into an automotive or industrial control environment. Both medium-field (50 mT) and high-field (120 mT) versions are available in three package options: SOIC-8, TSSOP-16 (dual-die for redundancy) and QFN-16 (with wettable flanks). All package options are qualified to AEC-Q100 covering the extended temperature range for -40 °C to +125 °C and are RoHS compliant.

The selectable digital output provides 16-bit resolution for X, Y and Z magnetic field measurements, enabling the host processor, DSP, microcontroller or digital signal controller to decode the absolute position of any magnet as it passes the sensor.

The MLX90395 is smaller and more power-efficient than alternative Hall effect sensors, thanks in large part to Melexis' Triaxis technology. This technology helps return an industry-low power consumption, with an idle current of 1.4 μA and standby current of 2.4 μA, and supply current of 4 mA or less.

Along with magnetic field sensors to measure three fields (Bx, By, Bz), the MLX90395 also integrates a temperature sensor and supply voltage monitor. Functionally, the sensor features three state machines and operates in one of three modes: single measurement, burst mode and wake-up on change mode. Engineers can select which magnetic field is measured and the frequency of measurement, to further fine-tune the sensor's energy efficiency as well as the filtering and sampling time to optimize noise vs bandwidth.

Operational modes can be defined and selected at runtime through the I2C or SPI interfaces, allowing multiple sensors to form part of a sensor cluster, controlled by a single microcontroller. The bus protocol (SPI or I2C) is also selectable, running at up to 10 MHz for SPI and 1 MHz for I2C. Each sensor is given a unique 48-bit ID number during the manufacturing process and contains additional free space to store customer traceability information.