Planar fluxgate current sensor integrated in printed circuit board

This paper describes the design and testing of a planar fluxgate current sensor, which is totally embedded in printed circuit board (PCB) and which is suitable for sensing currents in the printed circuit board traces. Fluxgate excitation and pickup coils are implemented as racetrack shaped copper winding in the printed circuit board internal layers. These are surrounded by an electroplated magnetic core consisting of a thin film of nickel iron alloy. The sensor has been tested over a 2 A current range. Sinusoidal excitation at 10 kHz, 30 kHz and 50 kHz has been used. The sensitivity has been measured at 200 mV/A for 50 kHz excitation. The power dissipation has been measured at approximately 2.6 W for a sinusoidal excitation.