2D CMOS integrated magnetometer based on the miniaturized circular vertical Hall device

Abstract

We present a CMOS integrated two axes magnetometer. The sensor contains a miniaturized 8-contact circular vertical Hall device as a sensing device, as well as the necessary biasing and signal conditioning electronics. A novel biasing of the device, signal retrieval and phase sensitive detection that involve all contacts were applied. This approach strongly suppresses offset and low frequency noise of the sensor in a similar way as the conventional spinning current method does. The magnetometer has sensitivity of 0.22 V/T for 0.2 mA Hall biasing current, low residual offset in the range 80-300 muT, low nonlinearity and 15 nV/radicHz input referred voltage noise.