MLX91206 Novel Contactless Current Sensor

Melexis takes a next step into driving green solutions by opening new opportunities for contactless current sensing in renewable energy applications, Hybrid Electric Vehicles (HEV) and Electric Vehicles (EV). The MLX91206 is a customer programmable monolithic sensor IC featuring the Triaxis™ Hall technology. The MLX91206 enables the user to construct small, economical current sensor solutions with fast response times. The chip directly monitors the current flowing in an external conductor such as a bus bar or PCB track.

The novel contactless current sensor MLX91206 consists of a CMOS Hall integrated circuit with a thin ferromagnetic layer structured on its surface. The integrated ferromagnetic (IMC) layer is used as a magnetic flux concentrator providing a high magnetic gain significantly increasing the signal to noise ratio of the sensor. The sensor is particularly appropriate for DC and/or AC current measurements with up to 90 kHz with ohmic isolation, very low insertion loss, fast response time, small package size, and low assembly cost requirements.

The MLX91206 meets the demand for widespread use of electronics in automotive applications, renewable power conversion (solar and wind power), power supplies, motor control, and overload protection. Typical uses are found in battery current monitoring, in solar power converters and automotive inverters driving the traction motor in Hybrid Vehicles HEV/EV. The MLX91206 features over-voltage and reverse voltage protection including broken track diagnostics and can be used as a “stand-alone” current sensor connected directly to a cable.

The MLX91206 senses current by converting the magnetic field generated by currents flowing through a conductor to a voltage that is proportional to the field. There is no upper limit to the measurable level of current because the output level is dependant on the conductor size and distance from the sensor. The transfer characteristic of the MLX91206 is fully customer programmable (offset, gain, clamping levels, and more). The output is selectable between analog and PWM. The linear analog output permits use where a very fast response of <10 μsec is required and a thermometer output signal monitors ambient temperature.