A recurring problem in electric vehicle design is that designers rely on shunt technology for its simplicity, but struggle to adjust the thermal threshold. As the current through the sensor increases, the resistance must decrease to maintain the same thermal losses (due to system imbalance). Similarly, designers using flow-gate technology to benefit from its galvanic isolation and high accuracy often fail to meet cost targets, in addition to consuming excessive power and space within the vehicle. These two recurring problems led Melexis to develop the MLX91230.

In terms of applications, the sensor is designed to suit a wide range of uses. For original equipment manufacturers (OEMs) and Tier 1 suppliers seeking to reduce production costs by internalizing DC sensing design, this digital device provides an accurate and reliable monitoring solution that also meets the highest functional safety requirements. For battery installations, it supports state of charge (SoC), state of health (SoH), and state of function (SoF) in both low- and high-voltage systems. It is ideal for battery management systems (BMS), battery disconnect units (BDUs), and battery junction boxes (BJBs).

The MLX91230 offers manufacturers of products such as power distribution components, contactors, and relays a safe and simple way to enhance the capabilities of their systems by incorporating intelligent functionality provided by the flash memory programmable microcontroller. Other innovative applications include smart pyro-fuses, where the MLX91230 can be used for local decision-making, and home energy storage systems such as solar power battery banks.

Thanks to its digital infrastructure and advanced signal processing, the MLX91230 can deliver unprecedented 1% accuracy in temperature and throughout its lifetime. Although other competitors' sensors have claimed this achievement before, the MLX91230 guarantees this accuracy not only for thermal drift but also for time drift and linearity errors. This represents a significant improvement over existing solutions.

The MCU with built-in flash memory supports custom software implementation and extensive compensation for system imperfections. Examples include ferromagnetic saturation, nonlinearities, and hysteresis compensation. The MCU also supports frame customization.

The MLX91230 complies with AEC-Q100 and ASIL standards. It supports system integration up to ASIL D according to ISO 26262 functional safety requirements. The digital architecture and flexible MCU enable easy integration into a variety of battery and DC voltage/current related applications.

The rise of electric vehicles and advanced driver assistance systems (ADAS) is placing increasing pressure on vehicle electronics design, whether to meet the latest functional safety requirements or to achieve design efficiency or cost targets. The MLX91230 boasts an unparalleled set of benefits designed to meet the latest automotive demands:

Hall effect-based DC current detection – provides galvanic isolation of current measurement. 0.5% temperature accuracy (from -40°C to 125°C) with a 1% lifetime drift.
IVT capability – measures three physical quantities: current, voltage, and temperature.
Flexible supply voltage – 5V (+/-10%) or 12V mains connection (compliant with LV124).
Diagnosable on-chip overcurrent detection (OCD)– allows direct input to the Pyro-Fuse controller.
Safety-of-Function Compliance (SEooC) – eliminates the burden of developing all safety mechanisms for the designer.
Digital MCU with programmable flash memory – enables advanced offsets, message customization, and intelligent system development.
Additional voltage channel: – Enables measurement with an internal divider (12V/24V/48V) or an external divider (high voltage or plausibility input). Facilitates battery resistance measurements, voltage safety/plausibility verification, or additional signal input.
On-chip junction temperature measurement: – Provides information on local temperatures.
Selectable LIN or UART output: – Enables integration with 12V battery applications and power distribution modules, as well as direct communication with a BMS or UART over CAN for communication through the wiring harness.
Compact IC design: – 8-pin SOIC package.

More

information