Smart IVT Hall and Shunt Sensors Accept External NTC Input
To enable more precise external temperature measurements in addition to junction readings, Melexis added an NTC resistor input capability to its MLX91230 (Hall-effect) and MLX91231 (shunt interface) sensors, thus enhancing its overall smart IVT (current, voltage & temperature) sensing platform.
The upgrade helps address the need for comprehensive monitoring in safety-critical applications: Integrating the NTC input into the MLX91230 and MLX91231 sensors improves the detection of variations in system temperatures.
For the MLX91231 (shunt interface), in particular, the improvement compensates the shunt resistor's residual variability over temperature, increasing current-sensing accuracy. Since the new NTC input is ASIL C compliant, it can also be deployed in safety-critical automotive applications, including automotive batteries, DC fast charging, smart pyro-fuses, and power-distribution modules.
Able to monitor and apply post-processing to the temperature of an external component using the same integrated circuit (IC) that performs current sensing, the sensors streamline development and improve system reliability. The ASIL C functional-safety compliance to ISO 26262 also applies to the current, voltage, and external NTC measurement. Diagnosable overcurrent detection also permits direct input to the pyro-fuse driver, allowing for the simple deployment of smart pyro-fuses with fewer components.
Each device is equipped with a microcontroller unit (MCU) complete with onboard flash memory, and the LIN output option facilitates integration with 12-V battery applications and power distribution modules. UART provides direct communication with the battery-management system (BMS). For remote BMS systems, UART-over-CAN can leverage a more robust physical layer while maintaining lower overhead layers above.
