The integration of an NTC input into the MLX91230 and MLX91231 improves the detection of system temperature variations. Specifically for the MLX91231 (shunt interface), it offers an additional use case for compensating for residual shunt resistance variability with temperature, resulting in further increased current sensing accuracy. Furthermore, the new NTC input is ASIL C compliant, enabling its implementation in safety-critical automotive applications such as car batteries, DC fast charging, smart pyrotechnic fuses, and power distribution modules. The

new NTC input pin allows engineers to monitor and post-process the temperature of an external component using the same integrated circuit (IC) that performs current sensing. With this expanded functionality, NTC-based current, voltage, and temperature measurements, both at the junction and outside the sensor, are measured by a single device, streamlining development and improving system reliability. Furthermore, compliance with ASIL C functional safety according to ISO 26262 applies to current, voltage, and external NTC measurements, as well as diagnosable overcurrent detection (OCD). The OCD also allows direct input to the pyrotechnic fuse controller, enabling the simple deployment of smart pyrotechnic fuses with fewer components.

These new features complement the already extensive functionality of the MLX91230 and MLX91231 sensors. Each device is equipped with a microcontroller unit (MCU) with integrated flash memory, facilitating the deployment of custom software and enabling robust compensation for any system discrepancies. Additionally, the LIN output option allows for easy integration with 12V battery applications and power distribution modules, while UART enables direct communication with the battery management system (BMS) that is beginning to be introduced in battery disconnect units (BDUs). For remote BMS systems, UART-over-CAN can leverage a more robust physical layer while maintaining the lower upper layers that characterize point-to-point communication between the sensor module and the BMS.

In addition to vehicle applications, the expanded capabilities of the new MLX91230 and MLX91231 will also benefit other high- and low-voltage battery solutions, such as battery energy storage systems (BESS), solar panel installations, and e-bikes, by providing accurate temperature monitoring for improved system management. “

With these additions, Melexis continues to build a comprehensive portfolio for battery applications, demonstrating our long-term commitment to this market,” says Bruno Boury, Product Line Manager at Melexis. “Temperature is a critical variable, as downsizing, faster charging, and more demanding use cases push systems to the limits of their thermal capacity.” The new NTC input of the MLX91230 and MLX91231 provides an additional temperature data point in environments with significant thermal gradients and enables DMC (data matrix code) shunt resistance compensation for more accurate current sensing.