DRIVING CIRCUIT OF MAGNETIC IMPEDANCE EFFECT ELEMENT

PROBLEM TO BE SOLVED: To reduce consumption power, eliminate difference of detection sensitivity which is due to the direction of an external magnetic field, and simplify structure. SOLUTION: This driving circuit is provided with a magnetic impedance effect element 5, an element driving circuit 3 applying a driving pulse to the element 5, a detection coil 10 wound around the element 5, a first sample-hold circuit 11 and a second sample-hold circuit 12 which hold a voltage detected by the detection coil 10, and a differential amplifier 9 outputting a voltage of difference between a voltage held by a first sample-hold circuit and a voltage held by the second sample-hold circuit 12. The detection coil 10 detects a voltage whose polarity is reverse at the rise time and the fall time of the driving pulse. A voltage of one polarity is held by the first sample-hold circuit 11, and a voltage of the other polarity is held by the second sample-hold circuit 12.