Automotive current sensor integrates an MCU for low-voltage measurement

Melexis has added the MLX91231, a shunt-based sensing automotive current sensor for IVT (current, voltage, and temperature) and a digital microcontroller (MCU).

The sensor is designed to measure low voltage electronics in vehicle safety systems. It has sensitivity drift error over temperature and lifetime below ±0.25% and a 1.5μV input referred offset drift error over the same conditions.

Integrating the microcontroller, with 32kbyte flash memory,° enables the sensor to provide current, voltage, and junction temperature readout via a selectable LIN or UART output. The microcontroller enables built-in diagnosable overcurrent detection which enables the safe triggering of pyro fuses without requiring a complicated safety mechanism.

The sensor is supplied by a regulated 5V or directly by 12V battery and is ASIL B(D) compliant as per ISO 26262. It also supports system-level integration up to ASIL D.



Target applications are close monitoring of low-voltage systems, such as dc-dc converters, battery terminal sensors and power distribution and monitoring in zonal infrastructure. Output stability and EMC resilience make it suitable for deployment in even the harshest of automotive environments, says the company.

Operating temperature is -40°C to +125°C. It is supported with custom software design which allows software reuse and is supplied in a compact eight-pin SOIC packaging which simplifies the system integration.

The shunt current sensor is tailored for DCDC converters, battery terminal sensors, low and high-voltage power distribution, and disconnection devices.


Leave a Reply

Your email address will not be published. Required fields are marked *

*