Boosting accuracy of Hall-effect DC current sensing

Melexis has released the MLX91230, the first product of its third generation of current sensors. This digital solution brings 0.5% accuracy at an affordable price in a compact design. It integrates IVT measurement capability, embeds an MCU to offload processing from the ECU and benefits from pre-installed safety features. The device is excellent for EV battery management and power distribution systems.

The sensor is designed to fit various usages. For OEMs and Tier 1 looking to lower production costs by in-sourcing DC current sensing design, this digital device delivers an accurate and reliable monitoring solution while meeting the highest functional safety requirements. It supports SoC, battery state of health and SoF for battery installations in both low- and high-voltage systems. It is ideal for BMS, battery disconnect units, and battery junction box deployments.

The device provides manufacturers of products such as power distribution components, contactors and relays with a safe and straightforward method of increasing their system’s capabilities by adding smart functionality delivered by the programmable flash microcontroller. Other innovative implementations include smart Pyro-Fuses, where the device can be used to deploy local decision-making, and in home energy storage systems such as solar power battery banks.

Thanks to the digital infrastructure and advanced signal processing, the device can deliver an unprecedented 1% accuracy over temperature and over a lifetime. While this achievement has been claimed by competing sensors before, it guarantees this accuracy not only for thermal drift but also lifetime drift and linearity errors. This denotes an incredible improvement versus existing solutions.

The MCU with onboard flash memory supports custom software deployment and extensive compensation of system imperfections. Examples are ferromagnetic saturation onset, non-linearities and hysteresis compensation. The MCU also supports frame customization.

The MLX91230 is AEC-Q100 and ASIL compliant. It supports system integration up to ASIL D per ISO 26262 functional safety requirements. The digital architecture and flexible MCU allow simple integration into various battery-related and DC voltage/current applications.

“Melexis’ third generation of current sensors for the battery platform represents the very latest developments in our extensive automotive and sensor knowledge. With this portfolio, we defined three key pillars: a dependable digital core, high accuracy and functional safety compliance,” said Bruno Boury, Product Line Manager Current Sensors at Melexis. “The MLX91230 displays how our technology can meet new industry requirements and delivers unparalleled accuracy. All while remaining both cost-effective and easy to integrate within a wide variety of applications.”