Ultra Low Offset Vertical Hall Sensor in CMOS Technology
This paper reports on a novel vertical Hall sensor with ultra low offset (ULOVHS) for the measurement of an in plane magnetic field component. The sensor consists of four parallel coupled fully symmetric vertical Hall sensors (FSVHS) Each FSVHS is formed by the connection of four identical three contact vertical Hall elements (3CVHE) As a result, with a bias current of 0.5 mA and after current switching, a mean residual offset of 0.27 mV with a standard deviation of 0.29 mV has been achieved among 40 samples on an 8 inch wafer, which is an improvement of a factor of 16 compared to the FSVHS (4.2+ 14 mV) Furthermore, the measured current related sensitivity of the novel device is SI 12.65 V/AT, allowing the detection of magnetic fields down to Bmin 40 mT without any additional electrical compensation circuitry. This represents the best results to date achieved by a standalone VHS in standard CMOS technology. (c) 2014 The Authors. Published by Elsevier Ltd. Peer review under responsibility of the scientific committee of Eurosensors 2014.