| 摘要 |
PROBLEM TO BE SOLVED: To detect whether an external magnetic field causing a malfunction is applied to an element without using a separately provided magnetic field sensor for external magnetic field detection.SOLUTION: A full bridge circuit comprises a first magnetoresistive element having a first polarity, a second magnetoresistive element having a second polarity, a third magnetoresistive element having a second polarity, and a fourth magnetoresistive element having a first polarity. A comparison circuit compares a first value indicating the difference between the electric potential of a first connection node and first electric potential with a second value indicating the difference between the electric potential of a second connection node and the first electric potential, and determines whether an external magnetic field exists on the basis of the comparison results. The direction of an initial magnetization vector of a magnetization free layer of the first magnetoresistive element is opposite to the direction of an initial magnetization vector of a magnetization free layer of the second magnetoresistive element. The direction of an initial magnetization vector of a magnetization free layer of the third magnetoresistive element is opposite to the direction of an initial magnetization vector of a magnetization free layer of the fourth magnetoresistive element.SELECTED DRAWING: Figure 1 |
