Open-loop CMOS Current Transducer with Low Temperature Cross-sensitivity

We present an open-loop CMOS current transducer without magnetic core consisting of a bus bar and a CMOS integrated magnetic sensor. The magnetic sensor is a combination of a circular vertical Hall device for low-frequency range and a pick-up coil for high-frequency range. The temperature cross-sensitivity of the Hall device is removed by measuring the angle of the magnetic field vector rather than its magnitude. The first measurement results show nonlinearity less than 1.5 % over 0-150 A range, wide dynamic range 0-2.8 kA, high slew-rate 14 MA/s and low temperature cross-sensitivity 500 ppm/degrees C over 100 degrees C. (C) 2011 Published by Elsevier Ltd