Patent ID: 7994782
Filing Date: 2011-08-09
Classification: G01R

Abstract:
1. A magnetic detection circuit to detect a magnetic field of a first polarity and a magnetic field of a second polarity, the magnetic detection circuit comprising a magnetic detection unit and a detection operation control unit, wherein the magnetic detection unit performs first and second magnetic field detection operations; the first magnetic field detection operation is that a magnetic field is detected according to a first control signal, that whether or not the detected magnetic field is of the first polarity is determined to obtain a first detection result, and that a signal showing the first detection result is stored; the second magnetic field detection operation is that the magnetic field is detected according to a second control signal, that whether or not the detected magnetic field is of the second polarity is determined to obtain a second detection result, and that a signal showing the second detection result is stored; the detection operation control unit gates the first control signal and the second control signal so as to allow both of the first and the second magnetic field detection operations to be performed, when both of the signal showing the first detection result and the signal showing the second detection result indicate that the magnetic field is not detected; and further the detection operation control unit gates the first control signal and the second control signal so as to allow only the detection operation of the magnetic field of the detected polarity to be performed, when either one of the signal showing the first detection result and the signal showing the second detection result shows that the magnetic field is detected.