Novel compact two-dimensional CMOS vertical Hall sensor

We report a novel compact CMOS sensor enabling the measurement of both in-plane magnetic field components B_x and B_y at the same location. The sensor consists of four n-wells arranged essentially as a square and electrically interconnected into a conducting loop. Four contacts, one at the center of each n-well, serve as drive and sense contacts. The sensing principle is the same as in established vertical Hall sensors. By selectively switching the interconnections among the n-wells, the device is made sensitive alternatively to B_x and B_y. The sensitivity for both directions is about 5.6 mV/VT. At a nominal B field of 3.7 mT the RMS error of the measured magnitude and angle of B are 56 μT and 0.8°, respectively.