Melexis Adds 5 V MLX90381 Pico-Resolver for Compact Motors

Melexis has introduced a 5 V version of its MLX90381 Triaxis pico-resolver for rotor position sensing in automotive, alternative mobility and robotics motor applications.

The MLX90381 5V uses Triaxis Hall technology with high-speed sine and cosine analogue outputs, providing an output refresh rate of 2 µs and measuring rotational speeds above 50,000 rpm. The sensor is housed in a 2.0 × 2.5 × 1.0 mm DFN-6 package and operates from -40°C to +160°C.

The new variant targets compact motor systems where conventional end-of-shaft position sensing may not be possible, including through-shaft motors, braking and steering motors, e-bike drives and robotic actuators.

Flexible Position Sensing Around the Motor Shaft

The MLX90381 5V measures magnetic flux density in three dimensions and allows engineers to select X/Y, X/Z or Z/Y magnetic axis pairs.

This provides more flexibility when positioning the sensor relative to the rotating magnet. In side-of-shaft and through-shaft motor designs, the sensor can be positioned below or close to the magnetic track rather than requiring additional space beside the assembly.

The approach can simplify PCB placement and tolerance management in motor designs where available mechanical space limits the position of the sensing electronics.

Rotor Position Sensing Above 50,000 rpm

With its 2 µs output refresh rate, the MLX90381 5V can measure rotational speeds above 50,000 rpm for rotor position detection in DC, BLDC and PMSM motor architectures.

The device provides high-speed sine and cosine analogue outputs, while programmable sensitivity and filter bandwidth allow its response to be configured for different motor systems.

I²C communication is included for device configuration and calibration during production.

160°C Operation for Automotive Motor Applications

The MLX90381 5V operates across a temperature range of -40°C to +160°C and includes embedded diagnostics. It is AEC-Q100 qualified and offers ASIL B SEooC capability for automotive designs.

Target applications include e-valves, seat motors, door handles, braking motors, steering motors, e-bike motors, cadence sensing and compact robotic actuators.

Samples of the MLX90381 5V are available now.

Learn more and read the original announcement at melexis.com.

Technology Overview

The Melexis MLX90381 5V is a Triaxis Hall-based pico-resolver for rotor position sensing in compact motor systems. It provides selectable magnetic axis pairs, sine and cosine analogue outputs, a 2 µs refresh rate and operation above 50,000 rpm from a 2.0 × 2.5 × 1.0 mm DFN-6 package.

FAQs

What is the Melexis MLX90381 5V?

The MLX90381 5V is a Triaxis Hall-based pico-resolver designed for rotor position sensing in compact DC, BLDC and PMSM motor systems.

How fast can the MLX90381 5V measure motor rotation?

The sensor has a 2 µs output refresh rate and can measure rotational speeds above 50,000 rpm.

Why does the MLX90381 support different magnetic axis pairs?

Engineers can select X/Y, X/Z or Z/Y axis pairs, providing greater flexibility when positioning the sensor relative to the rotating magnet in side-of-shaft, through-shaft and other mechanically constrained motor designs.