Melexis has used a digitally controlled, coreless technology that shrinks the size of a current sensor, writes Nick Flaherty.

The MLX91235 sensor eliminates the need for a ferromagnetic core, enabling the measurement of larger currents flowing through external primary conductors, including busbars.

The MLX91235 is smaller than typical sensors and eliminates hysteresis-related measurement errors. The differential measurement of the magnetic field between two internal sensing elements provides accurate current feedback.

With a 500 kHz bandwidth and 2 μs response time, the sensor is suitable for high-speed applications, such as motor-control and converter applications. It offers more precise and sophisticated compensation, resulting in a more accurate, smoother output.

Calibration is configured via a standard, serial peripheral interface (SPI), allowing this in-situ via any microcontroller unit.

Built-in, 16 bit, over-current detection (OCD) allows for asymmetric thresholds and includes two configurable ranges. It has a configurable detection time with a minimum duration of 2 μs and an optional debounce strategy, which helps to avoid false positives in harsher electromagnetic compatibility environments.

The MLX91235 is ISO 26262-compliant as an ASIL B Safety Element out of Context. This goes beyond the ASIL B requirements with a built-in self-test (BIST) that can be triggered via the SPI interface, enabling the report of temperature, under-voltage and mechanical stress.