Ultra-Low-Power Current Sensor Utilizing Magnetoelectric Nanowires

The fabrication and characterization of an ultra-low power current sensor utilizing magnetoelectric lead zirconate titanate/nickel zinc ferrite (PZT-NZF) nanowires is presented. Low-cost, low-temperature, and post-CMOS-compatible fabrication methods were utilized in the fabrication of a nanowire array. This array was electrically and mechanically flip-chip bonded onto a printed circuit board (PCB) with a current trace. The PCB also contained a low-power amplification circuit to provide buffering and a gain of 10. Characterization of the sensor up to 70 mA showed a sensitivity of 3.24 mV/mA, sensitivity error of 1.16%, nonlinearity of 4%, noise floor of <; 2 mA, and noise density of 8.4 nA Hz
^-1/2
at 1kHz. Lastly the only power consumption necessary for device operation was the power required for a low power op amp, 0.225 mW.