Abstract: A technique for an AMR-based sensing circuit allows current measurements over a wide frequency range. This is accomplished by folding the current carrying trace around the AMR sensor to concentrate and normalize the magnetic field generated by the current over a wide frequency range. Experimental results show that the sensor, when implemented with the proposed method, has an improved bandwidth of >10 MHz and enhanced sensitivity to high frequency currents evinced by the sensor output at DC or lower frequencies. The method is applicable for example in high frequency power converters where inductor current is used to control the ripple and transient response.

Abstract: A technique for an AMR-based sensing circuit allows current measurements over a wide frequency range. This is accomplished by folding the current carrying trace around the AMR sensor to concentrate and normalize the magnetic field generated by the current over a wide frequency range. Experimental results show that the sensor, when implemented with the proposed method, has an improved bandwidth of >10 MHz and enhanced sensitivity to high frequency currents evinced by the sensor output at DC or lower frequencies. The method is applicable for example in high frequency power converters where inductor current is used to control the ripple and transient response.