CODING INTERNATIONAL CO LTD

Hall Sensor

Melexis has provided a linear Hall sensor to be used as a current sensor.Having its fast response some time and improved stability over operating temperature and also over lifetime, the MLX91209CA is optimized for demanding current sensing applications.

Measuring electrical current inside a conductor is critical to a lot of systems. Classic measurement techniques use shunt resistors, current transformers or magnetic field sensors. Hall Effect sensors are often the choice when measuring DC currents.Nevertheless the new, improved MLX91209CA does apply in most current sensing situations. This versatile,high-speed Linear Hall IC,featuring a programmable sensitivity range between 5 to 150 mV/mT,is acceptable for measuring DC and AC currents up to 200 kHz.

The MLX91209CA’s strong thermal and lifelong stability provides design engineers with fully programmable critical characteristics – allowing a single part to satisfy a multitude of current sensing applications. Parameters such as sensitivity and offset are kept in an internal EEPROM memory. Calibration is completed using Melexis’ well-established, proprietary PTC (Programming Through Connector) protocol. This modulates the availability voltage and doesn’t require any additional pin for programming, enabling the most beneficial production flows. A linear analog output permits utilisation of the sensor in applications in which a extremely fast response of 3 µs is necessary.

Custom calibration is better performed in-situ following the sensor is fixed with regards to the current conductor and ferromagnetic core to ensure that a calibrated current sensitivity is achieved. Typical accuracy of the current sensing system based on the MLX91209 is better than ±0.5% at room temperature or ±2% over the full temperature range (from -40 °C - 125 °C) when applying in-circuit end of line calibration. These devices is supplied in the 4-pin SIP, RoHS compliant lead-free package.

Need for current sensing solutions keeps growing rapidly with all the increased proliferation of different vehicles, like Hybrid Electric, Electric and begin/Stop equipped ‘Mild Hybrids’. Battery management systems rely on accurate and stable current sensing to control the charge/discharge cycles. Proper management of the current in and out of modern batteries is essential for safety, battery service life and, in full electric vehicles, predictable range calculation.

Continued purchase of Solar Energy generation along with other grid connected powers demand accurate and stable monitoring to securely work on the rapidly expanding ‘Smart Grid’. Here,once more, current sensing is essential towards the control systems, for that effective integration of promising small to medium scale power generation systems.

Moreover, current sensing is instrumental within the control over power in additional traditional electronic systems. Power distribution systems in massive server installations rely on current sensing to provide high levels of up-time and predictive maintenance.