Melexis enhances its intelligent IVT (current, voltage, temperature) sensing platform by adding negative temperature coefficient (NTC) resistor input capability to the MLX91230 (Hall Effect) and MLX91231 (shunt interface). This upgrade enables more accurate external temperature measurement alongside existing junction readings, helping engineers meet the need for comprehensive monitoring in safety-critical applications.
The integration of the NTC input into the MLX91230 and MLX91231 sensors improves the detection of system temperature variations. In the specific case of the MLX91231 (shunt interface), it offers an additional use case to compensate for the residual variability of the shunt resistance with respect to temperature, resulting in a further increase in current sensing accuracy. Furthermore, the new NTC input complies with the ASIL C standard, 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 apply post-processing to 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—both at the junction and externally—are measured through a single device, streamlining development and improving system reliability. Additionally, ASIL C functional safety compliance per ISO 26262 applies to current, voltage, and external NTC measurement, as well as diagnosable overcurrent detection (OCD). The OCD also enables direct input to the pyrotechnic fuse controller, allowing for 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 enables simple integration with 12 V battery applications and power distribution modules, while UART allows direct communication with the Battery Monitoring System (BMS), which is beginning to be introduced in the Battery Disconnect Unit (BDU). For remote BMS systems, UART-over-CAN can leverage a more robust physical layer while maintaining the lower upper layers that characterize the current sensor module's point-to-point communication with 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,” said 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 on 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.”
The MLX91230 and MLX91231 are now widely available. Find out more at www.melexis.com/MLX91230 o www.melexis.com/MLX91231
