FLICKER NOISE AND OFFSET SUPPRESSION IN SYMMETRICAL HALL PLATES

For stable measurements of permanent or low-frequency magnetic fields, it is crucial to have a very good signal-to-noise ratio and low offse t voltage in Hall sensors. Flicker noise and offset in Hall plates are suppressed by orthogonal switching of a single symmetric Hall plate. The supply current alternates at 0=degrees and 90-degrees through the Hall plate. The Hall voltage alternates its sign, while the flicker-no ise voltage and offset voltage do not. With high-pass filtering, one g ets suppression of the flicker noise and offset voltage. A lower cut-o ff frequency for the flicker noise of the order of 10% of the switchin g frequency is introduced.